下列各句中，没有语病且句子表意明确的是 （ ）

They each _____ a CD in their bags.

reading room, we found her ________ at a desk,with her attention ________ on a book

In the past, he rarely spoke unless others were speaking about something that ______ to him.

Do you think it is fantastic ________ you to work with these disabled people— Yes, and I think it is brave ________ them to take part in the competition.