1. After people have learned that magnets attract things, centuries passed ____ they took note of the fact that magnets sometimes also repel things.

　　A. before B. until C. after D. since

　　2. He is off to Paris again tomorrow. He tells me that, with this journey, he ________ there and back twenty times.

　　A.will be B. will have been

　　C.will go D. will have gone

　　3. Many ways have been found_____small and simple machine to process large and complicated machine parts.

　　A. by using B. to use C. using D. used

　　4. I walked down the corridor, my footsteps_______frighteningly through the empty deserted building.

　　A. echoing B. echoed C. to echo D. having echoed

　　5. Apart from personal preferences, social context also affects—both directly and indirectly—the media and the media content to which you become exposed. For example, other members of the family often select media content that you _____, and you become exposed to it.

　　A. would not have selected B. should not have selected

　　C. must not select D. cannot have selected

　　1. Abefore應該理解成“(幾百年過去了,人們) 才……”; 如果用after應該是…after centuries passed they took note of the fact…; 如果用until, 應該是they didn’t take note of the fact that…until centuries passed。

　　2. B此句意為：“他明天去巴黎,加上這次, 他就去了二十次了�！备鶕�句意,應用將來完成時態(tài)。句中有back一詞, 故D不合適。

　　3. Bto use…, 不定式短語做way的定語, 只是因為定語太長,故將謂語前移,使句子避免頭重腳輕。by using表示方式, 做狀語用; using為動名詞, 不能做way 的定語, way要求不定式做定語; used, 無論從語法結構上還是從意義上都講不通。

　　4. A分詞短語做伴隨狀語, my footsteps與echo的關系是主動的,因此用現(xiàn)在分詞。另外, 分詞做伴隨狀語表示與謂語動詞的動作同時發(fā)生, 所以用其一般式。

　　5. A本句意為:“除了個人喜好外, 社會環(huán)境也會直接或間接地影響你使用的媒體和媒體的內容。例如, 家庭的其他成員常常選擇的媒體內容你就未必選, 可是你也得使用。”句中暗含了 “如果是你, 你就不會選” 的意思, 所以用虛擬語氣合適。should not have selected表示“本不應該選”; must not select表示“一定不要選”; cannot have selected表示“一定不能選”, 過于絕對。只有would not have selected 符合句意。