Complete the sentences with the proper forms of the words in the box.
| contrast，protect ，preserve ，balance，proposal，likely，contribute ，conduct ，donate ，prevent |
（1）How do they
preserve
preserve
food？
（2）Are you for or against his
proposal
proposal
？
（3）But if you do this，the friendship will
likely
likely
die.
（4）She made the
contrast
contrast
of this picture with that one.
（5）What we could do is to
donate
donate
some money for them.
（6）Your value is not what you possess，but what you
contribute
contribute
.
（7）Now we have a
balance
balance
of males and females in one class.
（8）We can do nothing to
prevent
prevent
this disease （from） spreading.
（9）We
conducted
conducted
an investigation into the issue，but we got no result.
（10）What do you think we have to lose if we fail to
protect
protect
our cultural heritage？
