Isn’t David an efficient manager?—Er, David is really great but sometimes he has problems ______his ideas.

It is obviously that his parents didn’tteach him good _______.

What do you think of his words— What he said sounds _______ .

Modern science has given clear evidence ________ smoking can lead to many diseases.(2011·天津，13)

When will you return the book to me —I’ll give it to you___________I finish it.