问题
单项选择题
对于锻造余热淬火来说,若延长锻造后淬火前的时间,则钢的()
A.硬度、强度和冲击韧度同时降低
B.强度、硬度下降而冲击韧度增大
C.强度、硬度上升而冲击韧度下降
D.硬度、强度和冲击韧度同时上升
答案
参考答案:A
对于锻造余热淬火来说,若延长锻造后淬火前的时间,则钢的()
A.硬度、强度和冲击韧度同时降低
B.强度、硬度下降而冲击韧度增大
C.强度、硬度上升而冲击韧度下降
D.硬度、强度和冲击韧度同时上升
参考答案:A
完形填空 | ||||
In our classroom you can see there is a l of a park on the back wall. You can also see many children _ 2 the park. There is a river in it. Near the river there are not 3 , but there are many trees. Many 4 _ are singing in them. Near the trees there are some old men. They are sitting at a table. They are 5 tea and talking. There are two girls over there. They 6 new blouses. They are talking near the river. We can also see two boats in the picture. One is _ 7 but in 8 boat there are many children. Are there any young men in the _ 9 ? Let me see, there are some. They are swimming now. What are the boys doing? They are 10 _ there. | ||||
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