直肠上动脉发自 ( )
A．肠系膜上动脉
B．肠系膜下动脉
C．髂内动脉
D．腹主动脉
E．髂外动脉
参考答案：B
I was just going to cut my rose bushes but someone _______ it. Was it you?
A．has done
B．had done
C．would do
D．was doing
我国科举制正式诞生于（ ）
A．隋朝
B．唐朝
C．明朝
D．清朝
