---Is he here now?---No, I ___ he ___ here by now.

A. thought, was   B. think, will be   C. think, is    D. thought, had been

He did the right thing ___ for some fresh air even in cold winter.

A. to keep the chidlren from going out    B. to prevent the childern from going out

C. to keep the children going out        D. to prevent the children going out

Since nobody is here, the meeting will be delayed until tomorrow. The underlined word means ___.

A. put on   B. put off   C. put up    D. put away