Do you know _____ (why / what) you are studying for?
句意：你知道你为什么在学习吗？what…for = why，该句最后有 for，故用 what，故答案为what。
2018年12月，张阿姨把4000元的存入银行，定期三年，年利率是2.75%到期后，应得利息______元.
Do you know _____ (why / what) you are studying for?
I don’t know _____ (how / why) so many people are looking at him.
They don’t know _____ (if / whether) to go or wait.
I really don’t know _____ (how much / how soon) the bridge will be finished.
She said _____ (that / if) it wouldn’t matter much.
The prices of the vegetables in this market are very _____ (high / expensive).
—I hate rainy days. —_____ (So do I / So I do).
He isn’t going to have the concert tonight, _____ (isn’t he / is he)?
It’s going to rain, _____ (isn’t it / is it)?
