--All the building materials have been washed away.---So I have heard. But there was no sign ______ a heavy rain was on the way last night.
The elderly need special care in winter, as they are _____ to the sudden changes of weather.
As students, we should devote ourselves _____ our study.
Seeing a _____ smile on his face, no one doubtsthat he will get through the driving test.
The first time he had a dinner with some high officials, he felt ____ uneasy.
Don't put your bicycle______ the window. The glass can be easily broken.