【单选题】下列叙述 不正确 的是
D.
氯水和过氧化钠都具有漂白作用,其漂白原理相同
【单选题】放在手心里就能熔化的稀有金属--镓,其沸点为 2403 °C,更奇妙的是镓熔化后在- 120 °C仍不易凝固;在常温下几乎不与氧气和水反应,但能溶于强酸和强碱;与其他金属熔合可改善合金的性能;与硫、硒等非金属化合可生成优质半导体材料。有关镓的用途叙述错误的是( )
【简答题】A.People are rarely interested in the same kind of news. B.People have different views about what a good newspaper is. C.People scan for the news they are interested in. D.Different people prefer diff...
【单选题】放在手心里就能熔化的稀有金属镓,其沸点为2403℃,奇妙的是镓熔化后在-120℃仍不易凝固;常温下,镓不与氧气、水反应,但能溶于强酸和强碱;与硫、硒等非金属化合可生成优良的半导体材料。以下有关镓的用途或性质的叙述中,正确的是()
【单选题】下列有关硅及其化合物的说法正确的是
C.
SiO 2 与纯碱高温生成CO 2 ,说明硅酸的酸性比碳酸强
D.
SiO 2 是非金属氧化物,它不与任何酸反应
【简答题】A.People are rarely interested in the same kind of news. B.People have different views about what a good newspaper is. C.People scan for the news they are interested in. D.Different people prefer diff...
【单选题】下面关于条件反射的描述,正确的是()
E.
任何无关刺激与非条件刺激结合一次就可形成条件反射
【单选题】Although often extremely critical of the medical profession as a whole, people are rarely willing to treat their personal doctors with equal ______.