—Have you finished the book?
---No,I’ve read up to_________the children discover the secret cave.
| A．which | B．what | C．hat | D．where |
The time is not far away____modern communications will become widespread in China’s vast countryside.
| A．as | B．until | C．before | D．when |
Hardly ___________the door when he rushed into the office out of breath.
| A．I opened | B．did I open | C．I had opened | D．had I opened |
We want such materials ________ can bear high temperature and pressure.
| A．that | B．as | C．what | D．which |
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 |