TO SAVE FRESH WATER, REMEMBER TO TURN ………. THE FAUCET AFTER USING...

14. - DE KIEM TRA TIENG ANH 9HKII LAN 1
DE KIEM TRA TIENG ANH 9HKII LAN 1

14. To save fresh water, remember to turn ………. the faucet after using it.

a. in b. on c. out d. off