根据提供的信息和语言素材设计教学方案，用英文作答。设计任务：请阅读下面学生信息和语言素材，设计一节课的教学方案。教案没有固定格式，但须包含下列要点：?teaching objectives? teaching contents?key and difficult points?major steps and time allocation?activities and justifications教学时间：45分钟学生概况：某城镇普通中学九年级(初中三年级)学生，班级人数40人，多数已经达到《义务教育英语课程标准(2011版)》四级水平，学生课堂参与积极性一般。

If global warming goes on like this, Maldives in the Indian Ocean__________in the century to come．
A.disappearsB.disappearedC.has disappearedD.is going to disappear

Mr． Smith used to smoke__________but he has given it up．
A.seriouslyB.heavilyC.badlyD.hardly

To establish the evaluation index system of evaluation of students' all-round development must include__________ ．
A.subject learning goalsB.general development goalsC.subject learning goals and general development goalsD.emotional goals

We have a very communicative__________ to teaching languages．
A.meansB.methodC.mannerD.approach

Many people believe the glare from snow causes snow-blindness． Yet, dark glasses or not,they find themselves suffering from headaches and watering eyes, and even snow-blindness, when exposed to several hours of "snow light"．The United States Army has now determined that glare from snow does not cause snow-blindness in troops in a snow-covered country． Rather, a man's eyes frequently find nothing to focus on in a broad expanse of barren snow-covered terrain． So his gaze continually shifts and jumps back and forth over the entire landscape in search of something to look at． Finding nothing,hour after hour, the eyes never stop searching and the eyeballs become sore and the eye musclesache． Nature offsets this irritation by producing more and fluid which covers the eyeball． The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result istotal, even though temporary, snow-blindness．Experiments led the Army to a simple method of overcoming this problem． Scouts ahead of a main body of troops are trained to shake snow from evergreen bushes, creating a dotted line as they cross completely snow-covered landscape． Even the scouts themselves throw lightweight, dark colored objects ahead on which they too can focus． The men following can then see something．Their gaze is arrested． Their eyes focus on a bush and having found something to see, stop scouring the snow-blanketed landscape． By focusing their attention on one object at a time, the men can cross the snow without becoming hopelessly snow-blind or lost． In this way the problem of crossing a solid white terrain is overcome．?The scouts shake snow from evergreen bushes in order to__________ ．
A.give the men behind something to seeB.beautify the landscapeC.warm themselves in the coldD.prevent the men behind from losing their way