Only when the villagers were faced with water shortage___ how serious the problem of water pollution was.
Let’sgotothelibrarythisafternoon,_____?
—_____Iturnontheradio? —You’dbetternot.Itisnoisyenoughinthisroom.
I_____suchamistakeagain.
He_____notpayunlessheispunishedtopay.
—_____IwaterthetreesonTuesday? —No,youneedn’t.