真核和原核生物都能切除内含子，产生成熟的mRNA和蛋白质。 ( )
参考答案：错
以（）为基础所计算的保险费称为纯保险费。
A.预定风险率和预定利率
B.预定死亡率和预定利率
C.预定收益率和预定利率
D.预定死亡率和预定风险率
Though _____ to see us, the professor gave us a warm welcome. [ ]
A. surprising
B. was surprised
C. surprised
D. being surprised
