1. It'l be dark soon so I think we () switch the lights on.

    can

    have to

    had better

    needn't

2. You () go into the water because this lake is too deep.

    mustn't

    needn't

    shouldn't

    can

3. You () get a special visa to cross the Russian border.

    should

    have to

    can

    needn't

4. In my opinion you () get into the water immediately after having a big meal.

    had better

    can

    shouldn't

    needn't

5. I () pilot helicopters now because I have just got my licence.

    should

    shouldn't

    had better

    can

6. You () take your purse with you because we are not going to buy anything.

    shouldn't

    had better

    needn't

    can