Inside the White House, there is a room called the Oval Office. That's ________ President Obama works.
| A．why | B．where |
| C．what | D．how |
94. I can hardly hear the radio. Would you please ____ ?
| A．turn it on | B．turn it down | C．turn it up | D．turn it off |
92. The international police has come into existence and they were ____ the key to global security.
| A．thus | B．for | C．or | D．Otherwise |
91. She likes to keep things rather than throw them ____ .
| A．out | B．off | C．down | D．Away |
90. ____ the work was very difficult, they managed to finish it in time.
| A．Because | B．Though | C．Therefore | D．But |
89. The task is hard, ____, the workers managed to finish it in time.
| A．therefore | B．otherwise | C．however | D．Yet |