. There are dirty marks/spots on her trousers ________ she had wiped her hands.
| A．where | B．in which | C．when | D．that |
The English teacherher students how to improve their comprehension skill since last week.
| A．has told | B．is telling | C．has been telling | D．will have told |
---- Sorry, I have to ______ now. It’s time for class.
---- OK, I’ll call back later.
| A．hang up | B．break up | C．give up | D．hold up |
Before a problem can be solved, it must be obvious ______the problem itself is.
| A．what | B．that | C．which | D．why |
In the global economy, a new drug for cancer, it is discovered, will create many economic possibilities around the world.
| A．whatever | B．whoever | C．wherever | D．whichever |
Shortly after suffering from a massive earthquake and to ruins, the city took on a new look.
| A．reducing | B．reduced | C．being reduced | D．having reduced |