—Such a mistake could have been avoided.
—Unfortunately, he _______ the mistake again and again.
| A．repeated | B．would repeat |
| C．had repeated | D．would have repeated |
The accident caused some _____ to my car, but it’s nothing serious.
| A．harm | B．injury | C．ruin | D．damage |
Not until he went through real hardship ______ the love we have for our families is important.
| A．did he realize | B．had he realized |
| C．he realized | D．he had realized |
Old-fashioned phones matter when wireless networks _____ in disasters.
| A．turn down | B．break down | C．turn out | D．break out |
Michelle found a job as a high school teacher which _____ spending quite a lot of time with students.
| A．enjoys | B．practices | C．involves | D．suggests |
No one ______ be more generous; he has a heart of gold.
| A．must | B．dare | C．need | D．could |