( )是编制产品要求文件并找出潜在的来源。
A．编制沟通计划 B．编制询价计划C．编制采购计划 D．编制组织计划
参考答案：B
Yao Ming is coming to visit our school. We will _____ at the airport. [ ]
A. take him off
B. pick him up
C. see him off
D. take him up
门机的四大机构是起升、（）、变幅、行走机构。
