It was considerate _____ you not to playthe piano while I was asleep.

Bamboo, which is a common plant in the south, is used ______ in buildings, food, furniture and so on. It is used to make clothes as well.

When ______ different cultures, we often pay attentiononly to the differences without noticing the many similarities.

下列各句中，没有语病的一句是（ ）

You have failed two tests. You’d better start working harder, ____ you won’t pass the course.