发动机排气管上的三元催化转换器主要降低()的排放。
A、CO和HC
B、HC和NOx
C、CO和NOx
D、CO、HC和NOx
参考答案:D
What will the weather be like? Some people say they can know what the weather will be like from birds. When they see birds fly high out to the sea , they know it is a nice day, because birds don’t like to fly out when it will rain. When the weather will be bad, the birds come back to the beach. A big wind may come with a rain. Birds do not like to fly in a big wind. They may sit in a tree when rain is coming. Other animals can also tell the weather. It’s a cloudy day. The rain is coming. Chickens aren’t quiet, and they are running here and there. Frogs(青蛙) are making big noise in the pool. If it is a nice day, the frogs will come out of the water.
A. 放 B. 落 C. 游 D. 飞
小题1:We can play beach soccer when birds ________.
A.fly in the sky
B.come back
C.play on the beach
D.B and C小题2:Where there is rain, frogs are not _________.
A.in the pool
B.out of the water
C.making a big noise
D.swimming in the water小题3:What’s the best title for the passage?
A.Weather
B.Birds
C.Sea
D.Rain
人的一切行为都是由需要引起的。