标语的话：Shut off cock thar faucet when brushing teeth。
完整：We shall shut off the thar faucet when we are brushing teeth。
简单地也可以版说：
标语的话：Keep tap/cock closed when brushing teeth。
完整：We shall/must keep the tap/cock closed when we are brushing teeth。
初二的小朋权友用这个：
Close tap when brushing teeth。
或者：We must close the tap when we are brushing teeth.