问题
单项选择题 A1型题
白色血栓的主要成分是（）
A.血小板
B.红细胞
C.单核细胞
D.纤维蛋白
E.中性粒细胞
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
白色血栓的主要成分是（）
A.血小板
B.红细胞
C.单核细胞
D.纤维蛋白
E.中性粒细胞
参考答案：A
| 完形填空。 | ||||
| We know that trees are useful in our everyday life. They 1 us many things, such as wood, oxygen, rubber, medicines and many other things. They can 2 tell us a lot about our climate. The following are the reasons. If you 3 a tree, you can see that it has many rings (年轮). Most trees grow one new ring 4 year. Because of this reason, we know 5 a tree is. A tree over a hundred years old means that it has more than a hundred 6 . When the climate is dry or very cold, the trees do not grow very much and their rings are usually 7 . When it is wet and warm, the rings are much thicker. If the rings are suddenly very thin or suddenly very thick, this means that the 8 changed suddenly. If we look at the rings of this tree, we can 9 about the climate for a hundred years. We can see 10 our climate is changing today. | ||||
|