下呼吸道感染的常见因素有
A.免疫机能受损
B.正常菌群失调
C.病原体的飞沫传播
D.空调系统污染
E.致病菌通过气道逆行感染
参考答案:A,B,C,D,E
阅读理解,完成下列句子。
Look at the picture. We can see a hill in it. On the hill there are some trees. There are some birds in the
trees. Behind the trees there is a house. There is a river near the hill. We can see a boat in the river. There are
two boys in the boat.
1. We can see a hill in the .
2. There is a house the trees.
3. There are some birds the tree.
4. There are in the boat.
5. The river is the hill.
下列关于柴达木盆地的说法错误的是( )。
A.面积大,是中国最大的盆地
B.沙漠广,塔克拉玛干沙漠是中国最大的沙漠
C.地势西高东低,海拔800--1300米,边缘有绿洲
D.内有平原、丘陵、低山分布