-Are Bill and Mike at home now?

-Yes. They _____ their mom cook. They often _____ their mom do housework.[ ]

A. help; are helping

B. are helping; help

C. helps; is helping

D. is helping;helps

“入芝兰之室，久闻而不知其香”说明的是

A．感觉过敏

B．感觉适应

C．感觉相互作用

D．感觉减退

E．感受性补偿