A good story does not necessarily have to have a happy ending, but the reader must not be left __________.

A．unsatisfied

B．unsatisfying

C．to be unsatisfying

D．being unsatisfied

能引起沙眼的病原体是

A．沙眼衣原体沙眼亚种

B．沙眼衣原体LGV亚种

C．沙眼衣原体鼠亚种

D．肺炎衣原体

E．鹦鹉热衣原体