患儿治疗效果不佳，出现四肢肌张力低下，腱反射不能引出，心率变慢、血压降低，患儿处于哪一期（）

A.Ⅰ期

B.Ⅱ期

C.Ⅲ期

D.Ⅳ期

E.Ⅴ期

--- What have you learned from your experience in Japan?

--- Well, meeting people from another culture ___ be very difficult.

A．must

B．can

C．should

D．shall