-How long have you been in the room?
- Just a few minutes. My cousins ___home together with me.
| A．have walked | B．had walked | C．walked | D．have been walking |
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 |
The two dogs started to fight, so we tried to _____ them.
| A．split | B．separate | C．tear | D．divide |
Japan has to employ an increasing number of overseas workers because there is no easy solution to its labor _____.
| A．decline | B．rarity | C．vacancy | D．shortage |