It was foolish of him to _____ his notes during that important test, and as a result, he got punished.       [ ]

A. stick to      

B. refer to    

C. keep to    

D. point to

直接连接大涎腺腺泡的导管是

A．纹管

B．小叶间导管

C．分泌管

D．闰管

E．排泄管