引起急性化脓性腮腺炎的病原菌有()

A．绿脓杆菌

B．金黄色葡萄球菌

C．链球菌

D．肺炎双球菌

E．奋森螺旋体

The old professor has such a bad memory that he looks for the watch while he is ___.

A．having it on

B．having on it

C．wearing it

D．putting it on