--- What about yesterday’s homework, Amy?--- I found ____ hard to finish all the exercises.

—The books are so nice, which one can I take? —Oh, you can take _______ of them. I’ll keep none.  

The weather in Guangzhou is hotter than ________ in Beijing in summer.

I think          important for us to learn a foreign language well.　　

— _______ does Tom like math? —Because _____ fun.