When about one of the biggest problems today, many experts say that an energy crisis is approaching and is thus threatening mankind's survival．
| A．asked | B．being asked | C．having asked | D．asking |
House prices vary from place to place and are usually high _____ there are famous schools.
| A．where | B．since | C．when | D．whether |
—Have you received your new shoes?
—Yes. And at the same time I got the jacket I _____.
| A．had ordered | B．ordered | C．have ordered | D．order |
As the intelligence of robots increases to match ________ of humans，we may use them to expand our frontiers.
| A．it | B．that | C．which | D．the |
Experts believe that language learning is a process ______ skills are more important than grammar rules.
| A．whose | B．when | C．of which | D．in which |
The warning of the storm, ______ over the radio and on TV, spread quickly through the province.
| A．broadcasting | B．having broadcast | C．broadcast | D．to be broadcast |