下图为“我国部分省区人口承载系数(实际人口密度与理论承载密度之比)及20世纪末人口流动示意图”，据图回答下列各题。
引起图中人口流动的最主要因素是
| A．经济因素 | B．社会因素 |
| C．生态环境因素 | D．政治因素 |
图中区域单位面积环境人口承载力最大的省区，其形成的最主要原因是
| A．矿产丰富，经济发达 | B．经济发达，对外开放程度高 |
| C．资源丰富，消费水平低 | D．耕地面积广阔，水资源丰富 |
Whether we’ll hold the sports meet depends on the weather, _____?
| A．won’t we | B．shan’t we |
| C．doesn’t it | D．won’t it |
I went to bed very late last night, _____, early the next morning.
| A．or rather | B．at least |
| C．at most | D．in a word |
She took the boy _____ the hand and led him _____ the zero.
| A．in…by | B．on…at | C．at…in | D．by…round |
We _____ a pleasant journey but for the rain.
| A．would have | B．will have |
| C．had had | D．would have had |
— Shall I go and buy two more bottles of beer?
— No, I’ve already bought twenty. That _____ be enough for us two.
| A．can | B．may | C．ought to | D．might |