等比数列{an}中,a4=4,则a2·a6等于
A.4
B.8
C.16
D.32
答案:C
a2·a6= a42=16,选C
Risk management allows the project manager and the project team not to()
A.eliminate most risks during the planning phase of the project
B.identify project risks
C.identify impacts of various risks
D.plan suitable responses
群体活动的目的大致分为哪两类()
A、完成任务
B、满足群体个人社会需要
C、获得心理上的认同感
D、团结一致以应付环境的威胁