液压系统装置中()是管线加油车特有的。
A、胶管卷盘机构
B、地井胶管收放机构
C、升降平台
D、回收油箱抽油泵机构
参考答案:B
—What is your friend doing?
—The boy is in the classroom now, doing _______ homework with others. [ ]
A. he
B. him
C. his
D. himself
下列关于机器语言程序与高级语言程序的说法中,错误的是()
A.机器语言程序比高级语言程序执行速度慢
B.机器语言程序比高级语言程序可移植性强
C.机器语言程序比高级语言程序可读性差
D.有了高级语言,机器语言就无存在的必要了