—Will you give me a hand? I have some trouble_______ the scientific problem.—Don't worry. I'll try my best to help you _______.
Each of us has to write a ______ report every two weeks.
Tens years ago, there _____ full of fish in the lake .Now there are _____ fish .
The doctor did what he could _____the dying man.
-How many workers are there in your factory? -______ the workers in my factory_______ over two thousand .
---I’m too busy________ to my family often. --- Why not call them instead ?