ZG80—1500型电力机车组合两组主电阻的电空接触器是（）号。
A.13
B.19
C.22
D.18
参考答案：A
句型转换。
1. We can wear hats in school. (变成否定句)
_____________________________
2. We can eat in the cafeteria. We can't eat in the classroom. (用but 将两句话连接起来)
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3. You have to wear sneakers for gym class. (变成一般疑问句,并作肯定回答)
4. I have to do my homework after school. (就划线部分提问)
5. I have to be in bed by ten o'clock. (就划线部分提问)
自然数a的最大的因数是它本身。[ ]
but 将两句话连接起来)