我们不确定那些练习能否按时完成．（benotsurewhether…）．

Question

我们不确定那些练习能否按时完成．（be not sure whether…）___．

Answer 1

答案：We are not sure whether those exersises can be finished on time．表达的是客观事实用一般现在时，表示不确定…用所给的be not sure whether…，主语we复数，故are，whether引导的宾语从句，后加陈述句语序，主语those exersises是动词finish的承受者，结合情态动词can能，用情态动词的被动语态---情态动词+be+过去分词，on time准时，故答案是We are not sure whether those exersises can be finished on time．