问题补充:
---Do you know mother giant pandas have only one or two babies?
----Sorry,I don’t know.
A. at a time
B. at time
C. at times
D. at that times
答案:
(答案→)A. at a time
B. at time
C. at times
D. at that times
解析:
试题分析: 句意:你知道大熊猫妈妈一次只生一个或两个宝宝吗?对不起,我不知道。at a time一次,at time无此短语,at times有时,偶尔,at that times无此短语。giant pandas大熊猫,have分娩。根据语境可知是一次生一个或两个宝宝,故选A