— Why do English people talk so often about the weather when they start a conversation?— Well, it’s probably the weather is a(n) __________topic.
_____ of their bad habits, the boys switched from being dependent on their parents to _____ for others.
Happy birthday, Alice! So you have _____ twenty-one already.
The computer was used in teaching. As a result, not only _____, but students became more interested in the lessons.
Teachers have to constantly update their knowledge in order to maintain their professional(专业的)_______.
Everything comes with _____ price; there is no such _____ thing as a free lunch in the world.