Xiao Li was supposed __________ her homework before nine o’clock. But she couldn’t.

We didn’t find the Blacks during the lecture — No one had told them about _____ a lecture

It’s ______ he helped you that I’m ready to help him

In the last ten years she_____ like this; she is killing her health.

The train goes at 8 o’clock.I’m afraid I can’t . [ ]