We need to get to the root of the problem ________ we can solve it.

_____it is raining, we had better take a taxi

What’s this in English—It’s an ________.

We find that many children seem to lose their natural drive (动力) ____ shortly after going to school, and end up ____ the ranks of failure. [ ]

A poet and artist_____ coming to speak to us about Chinese literature and paintings tomorrow afternoon.