—Our P.E. teacher isn’t as young as he _______, is he?

—No, but he is one of _______ in our school.

A．looked; the youngest teacher

B．looks; the youngest teachers

C．looks; the oldest teachers

D．looked; the oldest teacher

外源性致热源的特点，正确的是（）

A.分子量较小

B.其致热源性可被蛋白酶类所破坏

C.能激活血液中的中性粒细胞和单核细胞

D.直接作用于体温调节中枢

E.在体内最终由肝、肾灭活和排泄