17. On the way, you can see this sign and it warns that:

A. Road closed ahead.

B. No left turn.

C. No U-turn permitted.

D. No passing zone.

18. At the public, when we can see this sign, it means:

A. Washing your hands after using public services is extremely necessary.

B. Washing your hands is unnecessary

C. You shouldn’t wash your hands.

D. You should turn off the faucet.