单项选择题
A stream of water immediately surrounding a moving vessel’s hull，flowing in the same direction as the vessel is known as（）.
A.directional current B.forward current C.propeller current D.wake current
单项选择题 欧阳修是（）词人。
单项选择题 Leaking oil seals on a diesel engine turbocharger can cause（）
判断题 浓度越高，药物的作用越强，故用95%的乙醇消毒，效果更好。
