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问题 选择题

有一种放置在厕所、汽车、饭店内的“固体清新剂”，它散发出的气体能有效地清新空气、预防感冒等．这种“固体清新剂”发生的物态变化是（　　）

A．熔化

B．凝华

C．汽化

D．升华

答案

答案：D

单项选择题

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.

A. plane B. plant C. plate D. platform

A Web browser is simply a terminal emulator, designed to display text on a screen. The two essential differences between an ordinary terminal emulator and a Web browser are that the browser knows how to deal with (71) , and that it has a mechanism for (72) graphical files. Display text, display graphics, and (73) hyperlinks ——there’s 99 percent of the (74) value. That’s not to say that the manufacturers didn’t go all - out to attach a hyperactive efflorescence of useless capabilities onto their browsers. Remember when media channels in the browser were a big deal, instead of the clutter you can’t wait to delete from your favorites of bookmarks menu Remember when client -side Java applets were supposed to become the preferred (75) , for application development Remember frames and all their nasty side effects
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单项选择题

合成甲醇H/C的调整的目的是（）。

A、增加循环气分子量

B、提高合成甲醇产量

C、调节反应温度

D、提高系统压力
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