取三张蓝色石蕊试纸放在玻璃片上，然后，按顺序分别滴加65%的硝酸、98%的硫酸和新制氯水，三张试纸最后呈现的颜色是()

— The manager of the factory wants to improve production a great deal, but he doesn’t spend much on technology.

— I am afraid he won ’t realize his dream. You know ________.

The manager together with his two secretaries__________for Hong Kong to attend a meeting there.

在天体系统的层次划分中，太阳系属于：（）

我国周边陆上接壤的国家有()。