新概念英语第二册课后习题答案详解Lesson 21练习答案 Key to written exercises1关键句型练习答案A passing planes can be heard(1.2); The airport was built (1.2); it could not be used then(1. 3); a hundred people must have been driven away(11.4-5); this house will be knocked down by a passing plane(11.6-7); I have been offered a large sum of money(1.7)C 1 A message will be sent immediately.2 All these goods must be sold.3 I told you the parcel would be received in time.4 The letter has to be delivered by hand.5
