It is the test system, rather than the teachers, ____ is to blame for the students' heavy burden nowadays．
| A．who | B．this | C．that | D．whom |
Space exploration has been made ______ with the development of modern science and technology.
| A．it possible | B．it was possible | C．that possible | D．possible |
A mysterious illness, referred to as “ a typical phenomena”, has been brought under control, the government said on Wednesday, ______ no cause of it has been made public.
| A．though | B．when | C．that | D．because |
Before leaving home, make sure to turn off the electricity, lock the door, ______ the windows open.
| A．and not to leave | B．instead of leaving |
| C．rather than leave | D．and not leave |
The idea for the new machine came to Mr. Baker ______ to his invention recently.
| A．while devoting | B．while devoted |
| C．while he was devoted | D．while devoting himself. |
Professor Liu has ________ teach psychology since he came to the Central China Normal University.
| A．determination to | B．been determined to |
| C．been determining to | D．determined to |