—Will you give me a hand? I have some trouble_______ the scientific problem.—Don't worry. I'll try my best to help you _______.
---My father is ill, I have to look after him at home. ---
There ______ a parents’ meeting tomorrow afternoon.
We should stop people from_____ the street when the light is red.
_______ necessary for us _______ English well.
—Watching TV too much _______ bad for your eyes. —I’ll go to bed right away.