Question

11．我们不确定那些练习能否按时完成．（be not sure whether…）We are not sure whether those exersises can be finished on time．．

Answer 1

分析 We are not sure whether those exersises can be finished on time．

解答 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．

点评 be sure+宾语从句，表示主句主语对宾语从句中涉及的事物所作出的判断，意为"确信某事一定会…"．例如：
I'm not sure whether I've met him before．我不能确定以前是否见到过他． 
We are sure he will make great progress this term．我们确信他这学期一定会取得巨大进步