Why _______ you be so stubborn? You should think over my advice on this matter.
| A．may | B．shall | C．dare | D．must |
The passer-by jumped into the cold water to save the _____ boy, who cried for help, but it was too late and the boy was _______ at last.
| A．drowning; drowned | B．drowned; drowning |
| C．drowning; drowning | D．drowned; drowned |
The computer system _____ suddenly while he was searching for information on the Internet.
| A．broke down | B．broke out | C．broke up | D．broke in |
Cycling is highly _____ to people’s health and the environment.
| A．fashionable | B．beneficial | C．changeable | D．suitable |
I recognize her __I met her at the airport, although we haven’t seen each other for ten years.
| A．the moment | B．in the moment |
| C．for the moment | D．at the moment |
Unless ________ to speak, you should remain silent at the conference.
| A．invited | B．inviting | C．being invited | D．having invited |