简述影响反应时间的机体变量有哪些。

为什么说德育过程是提高学生自我发展能力的过程？

酵母基因组全序列的测定业已完成，结果发现根据序列确定的相邻基因间的物理距离(千碱基对，kb)与连锁图上的相应基因间的遗传图距(厘摩，cM)不成比例，如
A、B、C、D四个基因的物理距离为而遗传图距为。请问这种现象是正常的，还是不正常的？可否设计更精确的遗传分析实验解决这一矛盾？如何解决？并说明理由。

In this section, you are asked to write a letter based on the following statement. Your letter should be at least 150 words.

“五一”、“十一”长假丰富了人们的业余生活，促进了旅游经济的发展，同进也带来诸如交通拥挤、环境污染等问题。请就“黄金周” 的经济发展与环保问题向政府有关部门写一封信，提出自己的见解和建议。

Part B (10 points)

The volcano in the cornfield grew until it was bigger than the cornfield! (41)__ People called the volcano the Little Monster because it grew so fast. Scientists came from all over the world to study it and watch it grow. It is not often that people get a chance to watch a volcano from the very beginning.

Most of the volcanoes have been here for a very long time. Some have been here so long that now they are cold. They are called dead volcanoes. They have stopped throwing out fire and melted rock and smoke. It is safe to walk on them. Farms are plowed on the quiet slopes, and people have built houses there.

Some volcanoes have stopped throwing out hot rock, but they still smoke a little now and then. They are "sleeping" volcanoes. Sometime they may "wake up".

(42)______.

Today volcanoes are not so dangerous for people as they were a long time ago. Now we know more about why volcanoes do what they do, and we can usually tell when they are going to do it. (43)______.

People used to think dragons under the earth caused volcanoes. They said the smoke that puffed above the ground was the dragon's breath. They said the earthquakes were caused by the dragon's moving around down in the earth. Now we know that this is not true.

Another thing we know about volcanoes is that they don't happen just anywhere. (44)______. Scientists know where these places are, and maps have been made to let everybody know.

There are different kinds of volcanoes. Some explode so violently that the rock goes high into the air and falls miles away. A volcano may shoot out ashes so high that they float all the way around the world. They have made the sunsets green and the snow purple.

(45)______.

One very tall volcano stays fiery red at the top all the time. It is lucky that the volcano is near the ocean. Sailors can use it for a lighthouse.

[A] Other volcanoes are more gentle. The hot lava rises in their cones and overflows, rolling slowly down the mountainside, where it becomes cool and hard.

[B] Black smoke puffed out. Hot ashes fell like black snowflakes. Hot rock and fire and lava shot out.

[C] Smoke puffed up, and rock started popping up out of a crack that opened in the ground.

[D] A volcano named Vesuvius slept for a thousand years. But it woke up and threw out so much hot melted rock that it buried the buildings of two cities.

[E] Before a sleeping volcano wakes up, it usually makes a noise like faraway thunder, and the ground shakes in small earthquakes. People are warned and have time to get away safely.

[F] A volcano starts from a hole in the ground from which hot rock and smoke and steam come out. Far, far under the ground it is so hot that rock melts. This hot melted rock, or lava, is some-times pushed out of the earth through a hole or a crack in the ground. The steam inside the earth pushes the rock out.

[G] There are certain places under the earth where the rock is broken in a way that lets the steam and hot rock escape to the outside more easily.

(41)

Part B (10 points)

In the following article, some sentences have been removed. Choose the most suitable one from the list A—G to fit into each of the numbered blank. There are two extra choices, which do not fit in any of the gaps. (10 points)

Long before Man lived on the Earth, there were fishes, reptiles, birds, insects, and some mammals. Although some of these animals were ancestors of kinds living today, others are now extinct, that is, they have no descendants alive now. (41)___\_. Very occasionally the rocks show impression of skin, so that, apart from color, we can build up a reasonably accurate picture of an animal that died millions of years ago. That kind of rock in which the remains are found tells us much about the nature of the original land, often of the plants that grew on it, and even of its climate. (42)___\_. Nearly all of the fossils that we know were preserved in rocks formed by water action, and most of these are of animals that lived in or near water. Thus it follows that there must be many kinds of mammals, birds, and insects of which we know nothing. (43)___\_. There were also crablike creatures, whose bodies were covered, with a horny substance. The body segments each had two pairs of legs, one pair for walking on the sandy bottom, the other for swimming. The head was a kind of shield with a pair of compound eyes, often with thousands of lenses. They were usually an inch or two long but some were 2 feet. (44)___\_. Of these, the ammonites are very interesting and important. They have a shell composed of many chambers, each representing a temporary home of the animal. As the young grew larger it grew a new chamber and sealed off the previous one. Thousands of these can be seen in the rocks on the Dorset Coast. (45)______. About 75 million years ago the Age of Reptiles was over and most of the groups died out. The mammals quickly developed, and we can trace the evolution of many familiar animals such as the elephant and horse. Many of the later mammals though now extinct, were known to primitive man and were featured by him in cave paintings and on bone carvings.

A. The shellfish have a long history in the rock and many different kinds are known

B. Nevertheless, we know a great deal about many of them because their bones and shells have been preserved in the rocks as fossils. From them we can tell their size and shape, how they walked, the kind of food they ate.

C. The first animals with true backbones were the fishes, first known in the rocks of 375 million years ago. About 300 million years ago the amphibians, the animals able to live both on land and in water, appeared. They were giant, sometimes 8 feet long, and many of them lived in the swampy pools in which our coal seam, or layer, or formed. The amphibians gave rise to the reptiles and for nearly 150 million years these were the principal forms of life on land, in the sea, and in the air.

D. The best index fossils tend to be marine creature. There animals evolved rapidly and spread over large over large areas of the world.

E. The earliest animals whose remains have been found were all very simple kinds and lived in the sea. Later forma are more complex, and among these are the sea-lilies, relations of the star-fishes, which had long arms and were attached by a long stalk to the sea bed, or to rocks.

F. When an animal dies, the body, its bones, or shell, may often be carried away by streams into lakes or the sea and there get covered up by mud. If the animal lived in the sea its body would probably sink and be covered with mud. More and more mud would fall upon it until the bones or shell become embedded and preserved.

G. Many factors can influence how fossils are preserved in rocks. Remains of an organism may be replaced by minerals, dissolved by an acidic solution to leave only their impression, or simply reduced to a more stable form.