—Shall we go out for a walk?
—Sorry, I can’t. I _______ my homework.
| A．do | B．did | C．am doing | D．was doing |
Which of the following doesn’t belong to the Four Great inventions of Ancient China?
| A．Compass | B．Gunpowder | C．Paper-making | D．Printer |
Our planet is about years old.
| A．35,000 | B．4600 | C．4600 million | D．500 million |
can cause high blood pressure and hearing problems.
| A．Air pollution | B．Water pollution | C．Light pollution | D．Noise pollution |
is one of the greatest scientists, who won the Nobel Prize for physics.
| A．Yuan Longping | B．Bisheng | C．Yang Zhenning | D．Zheng He |
is the largest freshwater lake in China.
| A．Dongting Lake | B．Poyany Lake | C．Qinghai Lake | D．Hongze Lake |