根据下列句子及所给汉语提示，写出空缺处各单词的正确形式。（每空只写一词）

1）He has _______ ______ _________ (增加体重) since I last saw him.

2）He left his office job to try to _______ _______ ________ (谋生) on the land.

3）Bryson decided to quit _________ __________ (而不是) accept the new rules.

4）In winter, the town is often _______ _______（切断联系）by snow.

将市场调查分为探测性调查、描述性调查、因果性调查和预测性调查，是根据（）划分的。

A．调查间隔的时间 

B．调查的基本方法 

C．调查的目的性 

D．调查的空间范围