________ you are interested in astronomy, you can read the book.
Everything ______ doing is worthy of ______ well.
- Can I pay the bill by check? -- Sorry, sir. But it is the management rules of our hotel that payment ______ be made in cash.
______, but the idea of having to work more than ten hours a day without weekends discouraged me.
— How do you find the town you visited yesterday?— The town has changed out of all ______ in the past 20 years, a completely new one in front of me.
Green economy offers a new model ______ people could both protect the climate and develop the economy, according to what Li said at the International Cooperative Conference on Green Economy and Climate Change.