色谱分析中，提高热导检测器灵敏度的方法有哪些？

电视胸腔镜的简称是（）

A.VTAS

B.VATS

C.VSTA

D.VSAT

E.VTSA

Which of the following is NOT an assumption of the constant growth dividend discount model (DDM)（）

A. The growth rate of the firm is higher than the overall growth rate of the economy.

B. ROE is constant.

C. Dividend payout is constant.

He asked me　　　

A．which floor did I live

B．which floor I lived in

C．which floor I lived on

D．which floor I lived

下列国家不属于北欧的国家是（）。

A.瑞典

B.丹麦

C.芬兰

D.瑞士

氢氧化钡是一种使用广泛的化学试剂。某课外小组通过下列实验测定某试样中Ba(OH)₂·nH₂O的含量。

试样中Ba(OH)₂·nH₂O的质量分数为______。