引起伤寒不断传播或流行的主要传染源是()
A.普通型患者
B.顿挫型患者
C.慢性带菌者
D.恢复期患者
E.潜伏期患者
参考答案:C
I've tried by hard to improve my English.But by no means ________ with my progress. [ ]
A. the teacher is not satisfied
B. is the teacher not satisfied
C. the teacher is satisfied
D. is the teacher satisfied
ASR的中文含义是()
A.加速驱动防滑控制系统
B.电子制动力分配
C.电子稳定程序