It was _____ the old clock that the old man spent the whole morning at home.
— Smoking is bad for your health.— Yes, I know. But I simply can’t ____________ .
It was only when I reread his poems (诗) recently _____ I began to appreciate their beauty.
I ______ her to work hard at English, but she didn’t listen to me.
—How long ____ you ____ in Singapore?—For just the weekend. I’ll be back next Monday morning.
Every possible means ___ to prevent the air pollution, but the sky is still not clear.