他们不时地听到大卡车的轰鸣声。Now and then they heard the roar of a heavy truck.人群里不时发出几声抱怨和欢呼。Scattered groans and whoops broke out in the crowd.要抬起头，不时看看四周。Keep your head up, and look around you from time to time....
See if you can nail the chairman down to an exact date.看你能不能迫使主席把准确日期定下来。The main events were as follows: first,the president’s speech,secondly,the secretary’s report and thirdly,the chairman’s summing-up.主要活动如下:第一项,总裁讲话...