2-Complete the sentences with the correct form of the verbs in the box.
allow cause let make prevent stop

a)The water flows down onto the water wheel. This …………………cause……………….. the wheel turn.

b)The valve opens. This ……………allow………… the water flow in.

c)The valve closes. This …………make………… the water from flowing out.

d)The switch touches the contact. This …………………………………………. the electric current to flow.

e)The switch moves away from the contact. This …………….….. the electric current from flowing.

f)The water level rises. This ………………………… the float to rise.