The school board listened quietly as Jack read the demands that his classmates ______ forward.

A．be putting

B．had put

C．were put

D．have put

儿科发病率最高的一类疾病，首推（）。

A.肺系病证

B.心系病证

C.肝系病证

D.脾系病证

E.肾系病证