Question

They learned it all by themselves. That is to say nobody told them ________ .

A．what to do it

B．how to do it

C．where to do

D．when to do

Answer 1

B

试题分析：句意：他们是自学的这些技能。也就是说没有人告诉他们该如何去做这些事。本句考查特殊疑问词+to do做宾语；A项中it多余；C和D项少了it；结合句意可知，B项符合要求；故选B。