用倾斜平面法造斜，其（）应保持不变。
A．安装角
B．安装方位角
C．钻孔高边方位角
参考答案：B
－_______ leave at the end of this month.
－I don’t think you should do that until _________ another job.
A．I’m going to; you’d found
B．I’m going to; you’ve found
C．I’ll; you’ll find
D．I’ll; you’d find
要表示256级灰度图像，表示每个像素点的数据最少需要（）个二进制位。
A.4
B.8
C.16
D.256
－I don’t think you should do that until _________ another job.