7. Dave lost his job and was short of money, so ______his flat and move in with his brother.

A．that he did was to sell

B．what he did sell

C．what he did was sell

D．what he did sold.

在反射弧中，神经冲动的传导方向为（　　）。

A．效应器→传入神经→神经中枢→传出神经→感受器

B．感受器→神经中枢→传入神经→传出神经→效应器

C．感受器→传入神经→神经中枢→传出神经→效应器

D．感受器→传出神经→神经中枢→传入神经→效应器