Until the start of the Industrial Revolution, mankind was poor, hungry, and constantly at the _______ of disease and natural disasters.
| A．power | B．limit | C．control | D．mercy |
The time is not far away _____ modern communication will become widespread in China’s vast countryside.
| A．as | B．when | C．until | D．before |
I have never been to Beijing, but it is the place _____.
| A．that I want to visit it most | B．where I’d like to visit |
| C．in which I’d like to visit | D．I most want to visit |
_____ might be expected, the response to the question was very mixed.
| A．As | B．That | C．It | D．What |
Living in the central Australia desert has its problem, _____ obtaining fresh water isn’t the least.
| A．for which | B．to which | C．of which | D．in which |
All _____ is a continuous supply of the necessities of life.
| A．what is needed | B．for our needs |
| C．the thing needed | D．that is needed |