胶济路是全程在（）省境内的一条铁路线。
A、河北
B、山东
C、江苏
D、河南
参考答案：B
—— Nacy＿＿＿＿＿＿＿＿＿ the letter from her mother.
—— No, she can’t have. The postman hasn’t come yet.
A．can receive
B．can have received
C．must have received
D．must receive
秋季腹泻最常见的病原体是（）
A.柯萨奇病毒
B.合胞病毒
C.轮状病毒
D.腺病毒
E.流感病毒
