根据铆接（）的要求，铆钉的排列形式有单排、双排和多排等。
A.硬度和密封
B.强度和刚度
C.强度和密封
D.刚性和密封
参考答案：C
句型转换
1. It's Wednesday today. (对划线部分提问)
______ ______ ______ ______ today?
2. It's ten o'clock now. (对划线部分提问)
______ ______ ______ ______ now?
3. They do their homework in the evening.(改为否定句)
They ______ ______ their homework in the evening.
4. Let's go to play football. (改为同义句)
______ ______ going to play football?
5. have, lesson, at, two, I, a, chemistry, half, past
(连词成句)
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“人的感官是人认识外界事物的天然界限”，而思维却可以帮助人们突破这一天然的界限。这种观点表明思维具有（）
A、概括性
B、能动性
C、间接性
D、预见性
