影响钢液粘度的主要原因是什么？

—I wonder if you could go with me to the shopping mall.

—Don’t disturb me. I ______ my experiment report all the morning and haven’t finished yet.

A．wrote

B．was writing

C．have written

D．have been writing

长期食用甲基汞含量高的鱼贝类可致（）。

A.乌脚病

B.水俣病

C.变性血红蛋白血症

D.高铁血红蛋白血症

E.痛痛症

原始凭证是对经济业务按其性质加以归类，确定会计分录，并据以登记会计账簿的凭证。（）

---Ang Lee, a Chinese director, won the Best Director again in his_______ last year.

---How great he was! It was his ______ time to win an Oscar.

A．fifty, twice

B．fiftieth, second

C．fifties, second

D．fifties, two