牙目前认为人类龋齿主要致龋菌是()
A.乳酸杆菌
B.唾液链球菌
C.血链球菌
D.变形链球菌
E.轻链球菌
参考答案:D
He realized she was crying ________ what he had said.
A.because
B.becauseof
C.as
D.since
物流成本只包括储存、装卸搬运所发生的费用。