--What do you think of maths?

--My favorite. It’s ______ for me to study of all the subjects in school.

A．more difficult

B．the most difficult

C．less difficult

D．the least difficult

小儿原发性腹膜炎的感染途径

A．肝硬化并发腹水，肠腔内细菌通过肠壁进入腹腔

B．胸膜炎细菌经淋巴管穿过膈肌而至腹腔

C．肠伤寒穿孔肠内容物进入腹腔

D．经血行性感染

E．经女性生殖道的上行性感染