液压凿岩机与风动凿岩机相比，其优点是（）。
A.推力大，钻速快
B.冲击频率低，噪声小
C.没有油雾水气，作业环境改善
参考答案：A, B, C
综合填空。
I'm Jim. I'm a schoolboy. I'm seven. I'm _____(1) Class Two, Grade One. My father is in the jeep. His
name is Colin Smith. Julia is my mother. She _____(2) a round face. I ____(3) a brother and a sister. My
brother is Phillip. He's too small. He's at home. My sister is Maria. She's nine. She's in Class One, Grade Three.
I have a good friend. _____(4) name is Jim Black. We're in the _____(5) class.
十进制整数60转换成二进制数是
A．0111010
B．0111110
C．0111100
D．0111101
