---Jack can't concentrate on his study recently．
--- Yes, that might ____ why he did so badly in the last test．
| A．answer for | B．apply for | C．call for | D．account for |
The experiment show that proper amount of exercise, if ________ regularly, can improve our health.
| A．carry out | B．carried out | C．to carry out | D．being carried out |
Listen! Do you hear someone _________ for help?
| A．call | B．calling | C．to call | D．called |
His first book ________ next month is based on a true story.
| A．published | B．to publish | C．to be published | D．being published |
I’m not going to ________ their smoking any longer.
| A．catch up with | B．put up with |
| C．end up with | D．keep up with |
----- Our holiday cost a lot of money.
----- Did it? Well, that doesn’t matter ________ you enjoyed yourselves.
| A．unless | B．as soon as | C．as long as | D．though |