The farm as well as its neighbouring hills we once spent so much time _____ on a new look as recently as last year.  

A．on has taken

B．has taken

C．on having taken

D．having taken

炮制含挥发油类药物时应注意

A．低温干燥

B．润透泡透

C．避免蒸煮

D．高温干燥

E．长时间浸泡