– How many babies can a mother giant panda have ? – One or two.A. one timeB. at a timeC.

问题补充：

– How many babies can a mother giant panda have ?

– One or two.

A. one time

B. at a time

C. at times

D. some time

答案：

A. one time

(答案→)B. at a time

C. at times

D. some time

解析：短语辨析。one time 一次，一度； at a time每次，在某时；at times有时，偶尔；some time在未来某时。句意；大熊猫妈妈能一次生几个孩子？一个或者两个。结合语境，可知指的是每次，故选B。