The boy is strong enough to lift two chairs ________．
The boy is strong enough to lift two chairs ________．
A.at one time
B.at a time
C.at times
D.at the same time
答案及解析： B
at a time一次；at one time从前．
The boy is strong enough to lift two chairs ________．
A.at one time
B.at a time
C.at times
D.at the same time
答案及解析： B
at a time一次；at one time从前．