Little Tom has got a lot of birthday presents but he isn’t able to take all of them .A. o

问题补充：

Little Tom has got a lot of birthday presents, but he isn’t able to take all of them .

A. on time

B. at a time

C. at same time

D. from time to time

答案：

A. on time

(答案→)B. at a time

C. at same time

D. from time to time

解析：此题重点考查对四个短语的区别。