Isn't it time that children         to bed since it is too late?

Whoever is never ______ with the progress he has made will be a success. 

There’s no way of knowing why one man makes an important discovery ___ another man, also intelligent, fails.

Of all the books on the shelf,        is of any use for improving our practical skills of survival in the competitive world.

 To their great _______, they found their son arrived home safe before the storm.

My uncle invited me to spend the Spring Festival with him in Shanghai, but _______ I’d prefer to go on a tour in Hainan.

She is a woman of strong ______ and we all believe she will be a good leader.

 The company saw it as part of its social ______ to provide education for its workers.

It's OK to________an electrical appliance on so long as you are using it.

Learn some relaxation exercises and do them every time you feel________.

Everybody needs calcium, but it is quite possible for a similar person to be totally healthy by eating only________.

—We________gas.I'm afraid we can't go much further.—I know there's a gas station ahead.Sure it will last us until we get there.

Sara enjoys amusing her friends by________stories.

Have you thought about the problem from every________？You can never be too careful!

The successful launch of Tiangong­1 symbolizes a further step for China to join in the________of space stations previously mastered by Russia and the US.

—Have you heard that George quit his job?—Yeah, but I can't________why he did so.

—Sorry for the delay.I got lost in the mountain.—That's OK.You're safe and that's what________.

(2013·高考江西卷)Whenever I made mistakes，the teacher pointed them out with________.

(2013·高考湖北卷)Carbon dioxide，which makes a________between us and the sun，prevents heat from getting out of the atmosphere easily，so the earth is becoming warmer.

(2013·高考湖北卷)Poetry written from the________of the urban youth tends to reveal their anxiety over a lack of sense of belonging.