China ______ the WTO for more than 10 years, and it has brought great changes to it.

I want to return the book to John, but I can’t find him.–He­­­­______ the library. You can find him there.

Let’s stop _______ a rest. I am so tired.

Your mother prepared delicious food for us yesterday. Please say thanks ____ her.

I spent S 5 this book.[ ]