可引起肝脏疾病的主要有（）
A.钙
B.铜
C.钾
D.钠
E.铁
参考答案：B, E
. The new English teacher as well as the excited students _____ a new English song on the Internet.
A．are learning
B．is learning
C．have learned
D．has been learned
零切黏度
