____ she came in,i was writing a letter A when B while C since D where

问题描述:

____ she came in,i was writing a letter A when B while C since D where

A
题意:她进来时,我正在写信.____ there is no rain,it's difficult to plant trees A where B when C which D How 到底选 A,还是B?? 就这一题了!!好了就采纳!~\(≧▽≦)/~啦啦啦 今天晚上做好!Bwhen在此引导时间状语从句,但有条件的意义。题意:如果没有雨水,植树不有点困难了。