—What’s your math teacher like?   

—_________.

A．He’s twenty-seven years old

B．He works in our school

C．He’s creative and outgoing

D．He likes physics and biology

麻黄的主要有效成分为()

A．麻黄碱

B．伪麻黄碱

C．N-甲基麻黄碱

D．去甲基麻黄碱

E．去甲基伪麻黄碱