1871年是船政造船最旺盛一年，先后开工的兵船共计4艘，他们分别是“镇海”号，“靖远”号，“飞云”号和（）？

A、济安

B、安澜

C、威远

D、扬武

Mobility is one of the characteristics often （） executives, and they must accustom themselves to moving quite regularly.

A. demanded of

B. asked for

C. expected from

D. called for