He expressed a hope _______ he would visit China again the next year, and this was the very hope ________ he would express as soon as he arrived in the country.

A．that; that

B．which; which

C．that; which

D．which; that

水中有机氯农药测定方法有比色法、薄层法和气相色谱法等，其中灵敏度最高，且被广泛应用的方法是

A.比色法

B.薄层法

C.气相色谱法-氢火焰离子化检测器

D.气相色谱法-电子捕获检测器

E.气相色谱法-火焰光度检测器