确定（）是整个定员工作的核心。
A.定员水平；
B.定额标准；
C.定员比例。
参考答案：A
Had I known you wanted to go fishing, I _____ you yesterday morning. [ ]
A. need have called
B. would have called
C. can have done
D. must have called
“有效边界”指可行域的（）。
A．上边界部分
B．下边界部分
C．左边界部分
D．右边界部分
