Look!One of the children in the river.A. was swimmingB. is swimmingC. are swimmingD. were

问题补充：

Look!One of the children in the river.

A. was swimming

B. is swimming

C. are swimming

D. were swimming

答案：

A. was swimming

(答案→)B. is swimming

C. are swimming

D. were swimming

解析：根据Look!，用现在进行时，且主语是!One of the children，谓语要用单数，选B。，