Mr. White can always make us relaxed. He is _________ teacher I have ever met.

Of all Gong Linna’s songs, I like her Uneasy（忐忑）________.

—We're doing a lot to protect our environment, but it is not good enough. —So we should try______ to look after it.

Shanghai is bigger than _________________ city in Japan.

—You see, “Food Safety” receives thousands of Internet hits a day. —Yes, it becomes one of the _________ topics(话题) these days.