取14.3gNa2CO3•10H2O溶于水配成100ml溶液，（列式并计算） 求

She is _____ newcomer to _____chemistry but she has already made some important discoveries.

A．the; the

B．the; /

C．a; /

D．a; the

如果∠A和∠B的两边分别平行，那么∠A和∠B的关系是（　　）

A．相等

B．互余或互补

C．互补

D．相等或互补

试述国际避税的客观基础和主要方法。