I find __________ very difficult to learn English well .

 ---We can use QQ to talk with each other on the Internet.---Really? Will you please show me         it?

—I don’t like this pen. Could you show me      ? —Ok. Here you are.

--- Is this your sister’s key, John?--- No, it isn’t. ______ is in the bag.

I like junk food so much because ______ really delicious.