they have been expecting a splendid crop.that's what they have been___1 waiting 2 waiting for 3 waiting to 4 waiting on请问选择哪一个,及分别说出为什么对与错
问题描述：
they have been expecting a splendid crop.that's what they have been___
1 waiting 2 waiting for 3 waiting to 4 waiting on
请问选择哪一个,及分别说出为什么对与错
答
2
答
2
wait 是不及物动词,作“等待”讲,必须和for 连用,所以不选1 （没for),3,4(介词不对）