Brown said he was by no means annoyed; ______, he was glad to be able to make himself clearly understood.

A．all in all

B．for one thing

C．on the contrary

D．by the way

溴化锂吸收式溶液添加辛醇后能使冷凝器中发生（）。

A.珠状凝结

B.层状凝结

C.浓度的改变

D.压力的改变