燃油中的硫分对缸壁产生的硫酸腐蚀,缸套上部较下部()。
A.轻
B.重
C.较重
D.严重
参考答案:D
补全对话。
A: Excuse me. What day 1_____ yesterday?
B: It was Sunday.
A: 2_____ you very busy?
B: Yes, I was very busy.
A: What 3_____ you do?
B: I did my homework first. Then I 4_____ to the park with my parents.
A: How did you go there?
B: By bus. We 5_____ a good time in the park.
A: Where did you have lunch?
B: In the park. We had milk and bread for lunch.
AIDS主要病理变化表现在
A.肺
B.肝
C.骨髓
D.淋巴结和胸腺
E.脾