下列关于质点的说法，正确的是 A．研究宇宙飞船在轨道上的运动时，飞船不能看作质点

分析《茶馆》“葬送三个时代”的主题思想。

操纵能力受到限制的船包括：（）

A．从事拖带作业的船舶

B．在航中从事补给的船舶

C．限于吃水的船舶

D．失火中的船舶

When I was at a loss, the thought of traveling abroad did _____ to me.

A．occur

B．happen

C．strike

D．belong

With respect to the Standards of Professional Conduct relating to diligence and reasonable basis, which of the following statements is least accurate A member needs to:

A. ensure that his firm has standardized criteria for reviewing external advisers.
B. have an understanding of the parameters used in the model or quantitative research.
C. dissociate from team research reports that do not reflect the member's opinion.

GPON系统的ODN网络中，使用的光纤类型是（）

A.多模

B.双模

C.以上都是

D.单模