— I like speaking better than listening in English learning.—Oh, really? I think you should be good at          of them.

 More and more people find ______ necessary to protect our earth. 

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

 -- Did you read a book about customs last week?-- Yes, I found ______ very useful to know the customs of foreign countries.

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