The country has already sent up three unmanned spacecraft，the most recent ________ at the end of last March.
| A．has been launched | B．having been launched |
| C．being launched | D．to be launched |
------Flight 302 to London_______ until 7:30 tomorrow morning.
-----No wonder I hear so many complaints from the passengers.
| A．has been delayed | B．delay | C．delayed | D．will be delayed |
When the American constitution ______into effect in 1789,it didn’t contain any words guaranteeing the basic rights of ordinary citizens.
| A．went | B．had gone | C．has gone | D．was going |
----How have you been doing recently?
----________.Nothing really goes wrong.
| A．Good luck! | B．I’ll keep my fingers crossed | C．Can’t complain | D．So long |
A beach house caught fire last night, ______seven students living in it.
| A．to kill | B．killing | C．having killed | D．killed |
The computer system____suddently while he was searching for information on the Internet.
| A．broke down | B．broke out | C．broke up | D．broke in |