第7题: [单项选择]Why could maglev trains replace short-flight commuter aircraft A. Maglev trains are faster. B. Maglev trains are more fuel-efficient. C. Maglev trains are cheaper. D. Maglev trains are safer. 参考答案:C
第24题: [单项选择]By the end of next month we ______ this assignment. A. will finish B. will be finishing C. will have finished D. have finished 参考答案:C 答案解析:本题考查时态。介词by在这里表示“到……时候为止”。如果by表示将来的时间状语连用,句子时态用将来完成时,选项C正确。