高压断路器必须与高压隔离开关串联使用，由断路器接通和分断( )，由隔离开关隔断(

肝细胞对胆红素的转化主要发生在()

A．微粒体

B．线粒体

C．滑面内质网

D．粗面内质网

E．溶酶体

旅游企业品牌经营的实质是（）

A．提升品牌知名度

B.提高品牌忠诚度

C．提升品牌美誉度

D．品牌价值保值增值

Why do plants grow in some places and not in others? Why does some land have so much growing on it, while other land has almost no plants growing on it at all?

To grow, plants need several things. One is warmth. In very cold places almost nothing grows. Plants also need water. In very dry parts of the earth only a few unusual plants can grow. That’s why dry deserts everywhere are almost not covered by trees or grass.

Plants must also have a place in which to put down their roots and grow. They find it difficult to grow on hard land. The town is built on hard land. The plants here have only the soil found between the cracks of the stones to grow in.

Another thing plants must have before they can grow is food.

What will happen if we try to make things grow on the sandy beach? A few plants, such as beach grass, will grow in sand, but most plants won’t. Even if the weather is warm enough and we water the plants each day, many of them will die because the sand on this beach has almost no food for plants.

小题1:What things don’t most plants need to grow well according to the passage?

A．Warmth.              B．Food.                C．Sandy beach

小题2:What does the underlined word “cracks” mean in the passage?

A．表面             B．缝隙                 C．夹层

小题3:From the passage, we know that it is        for plants to grow in dry places.

A．difficult                B．impossible           C．important

小题4:The reason why most plants can’t grow on the sandy beach is that       .

A．there isn’t enough sunlight

B．there is too much water

C．it has little food for plants

小题5:The passage can most probably be found in a        book.

A．science              B．history              C．travel

有“世界屋脊”之称的高原是 [ ]

A、青藏高原

B、内蒙古高原

C、黄土高原

D、云贵高原

有毒，服用过量可引起肢体颤动、惊厥、呼吸困难、甚至昏迷等中毒症状，须严格控制用量，注意炮制的药物是（）

A．雄黄

B．炉甘石

C．白矾

D．马钱子

E．蛇床子