医院感染管理专职人员每年参加预防、控制医院感染相关知识的继续教育课程应不少于

A．3学时

B．5学时

C．6学时

D．10学时

E．15学时

The main idea of this passage is that ______.

A．light causes sea color

B．sea coloration is varied because of a combination of length of light waves and micro- scopic plant life and silt

C．microscopic plant life causes sea color

D．water composition causes sea color