Complete the sentences with the given words in their suitable forms. (共8分)Some parents purchase new _______________ (toy) for their kids before Christmas.
All the classmates took the difficult exam, but only _______________ (fifth) of them passed.
They were proud to say these paintings belonged to _______________ (they).
The professor made an interesting _______________(speak) at the meeting.
Children were fond of reading _______________ (excite) stories in their free time. e
They had a(n) _______________ (happy) trip because of the bad weather.
PM2.5 is _______________ (main) caused by air pollution in some parts of the country.
The doctor is ready to _______________ (operation) on his broken leg.