Not until he went through real hardship ________the love we have for our families is important.
| A．had he realized | B．did he realize | C．he realized | D．he had realized |
Scientists are convinced the positive effect of laughter physical and mental health.
| A．of; at | B．by; in | C．of; on | D．on; at |
If you really have to leave during the meeting, you’d better leave ____ the back door.
| A．for | B．by | C．across | D．out |
Let’s learn to use the problem we are facing ________ a stepping-stone to future success.
| A．to | B．for | C．as | D．by |
The house still needed a lot of work, but _______the kitchen was finished.
| A．instead | B．altogether | C．at once | D．at least |
Modern equipment and no smoking are two of the things I like ____ working here.
| A．with | B．over | C．at | D．about |