第23题: [单项选择]______ nobody has anything more to say, let's round off the discussion. A. When B. While C. So that D. Now that 参考答案:D 答案解析:本题为语法结构题,考从句与主句的逻辑关系。now that 意为“既然;由于”,表示因为某件事情发生了,所以就有了另一件事情的相继发生。这里不仅仅表示时间上的先后顺序,还表示一种因果关系。在本句中,讨
第29题: [单项选择]Although beavers rarely remain submerged for more than two minutes, they can stay underwater ___fifteen minutes before having to surface for air.
A. as long B. as long as C. so long D. so long that 参考答案: