Since the Obama administration took office, the China—US relations ________ positive development thanks to joint efforts of both sides, President Hu said at the Nuclear Security Summit in Washington, April,12,2010.
| A．witnessed | B．were witnessed | C．had witnessed | D．have witnessed |
The elderly ______ good care of in public places like supermarkets and airports; they are likely to get lost.
| A．can have been taken | B．ought to be taking | C．must be taken | D．should take |
Children need to feel ______ in order to do well at school.
| A．secure | B．fun | C．popular | D．threatened |
In the past few years, so many areas throughout the world have been hit by such destructive earthquakes, snowstorms and tsunamis ______ we have never experienced before, ______ makes us worried a lot about nature disasters.
A. A. that; that B. as; which C. which; it D. when; as
The computer is absolutely ______ amazing technological revolution. Just imagine what ______ fun it is playing computer games over the weekend!
| A．the; the | B．an; 不填 | C．不填；a | D．an; a |
The purpose of the new plan is to make life easier, ______ it more difficult.
| A．not make | B．not to make | C．not making | D．do not make |