One possible benefit of the experiment discussed in the passage is__________.
A.less crowded citiesB.victory over deathC.protection against fatal injuryD.fewer deaths from heart attacks

According to the passage, what is one disadvantage of skyscrapers that have mirroredwalls?__________
A.The exterior surrounding air is heatedB.The building materials are very expensiveC.Construction time is increasedD.Extra air-conditioning equipment is needed

The passage shows that__________.
A.mother was cold on the surface but kind in her heart to her daughterB.mother was too serious about everything her daughter had doneC.mother cared much about her daughter in wordsD.mother wrote to her daughter in careful words

On Venus there is a lot of__________.
A.waterB.carbon dioxideC.carbon monoxideD.oxygen

根据下列内容，回答186-190题。I've loved my mother's desk since I was just tall enough to see above the top of it as mothersat writing letters. Standing by her chair, looking at the ink bottle, pens, and white paper, I de-cided that the act of writing must be the more wonderful thing in the world. Years later, during herfinal illness, mother kept different things for my sister and brother."But the desk," she'd said a-gain, "it's for Elizabeth."I never saw her angry, never saw her cry. I knew she loved me; she showed it in action. Butas a young girl, I wanted heart-to-heart talks between mother and daughter. They never happened.And a gulf opened between us. I was "too emotional". But she lived "on the surface".As years passed I had my own family. I loved my mother and thanked her for our happy fami-ly. I wrote to her in careful words and asked her to let me know in any way she chose that she didforgive me. I posted the letter and waited for her answer. None came. My hope turned to disap-pointment, then little interest and, finally, peace--it seemed that nothing happened. I couldn't besure that the letter had even got to mother. I only knew that I had written it, and ! could stop try-ing to make her into someone she was not.Now the present of her desk told, as she'd never been able to, that she was pleased thatwriting was my chosen work. I cleaned the desk carefully and found some papers inside--a photoof my father and a one-page letter, folded and refolded many times. Give me an answer, my letterasks, in any way you choose. Mother, you always chose the act that speaks louder than words.The writer began to love her mother's desk__________.
A.after mother diedB.before she became a writerC.when she was a childD.when mother gave it to her

The word "gulf" in the passage means__________.
A.deep understanding between the old and the youngB.different ideas between the mother and the daughterC.free talks between mother and daughterD.part of the sea going far in land