He must have lived here for 10 years, _______ he?
| A．mustn’t | B．haven’t | C．didn’t | D．hasn’t |
She has lost her handbag with the _____ sum of $150 in it.
| A．extraordinary | B．important | C．considerable | D．valuable |
Many people complain of the rapid _____ of modern life.
| A．rate | B．pace | C．speed | D．growth |
The government is _____ and will take the necessary steps to maintain security and stability.
| A．on the alert | B．out of control | C．on guard | D．in vain |
Carl wanted to play a joke on Bob but gave himself _____ by laughing.
| A．away | B．in | C．out | D．up |
The rapidly growing birth rate brings about a lot of environment problems, which the government is supposed to take _____.
| A．significantly | B．severely | C．earnestly | D．seriously |