A:SO2通入品红溶液,溶液褪色后加热恢复原色;则SO2通入溴水,溴水褪色后加热也能恢复原色。
B:有些化学反应不属于化合、分解、置换、复分解中的任何一种反应
C:一种元素可能有多种氧化物,但同种化合价只对应一种氧化物
D:同一种元素的各种同位素的化学性质不同
将下列陈述句改成反问句。
①不劳动,连棵花也养不活,这是真理。
②我们不能因为学习任务重而不参加体育活动。
With the development of science and technology, our daily life is becoming more colorful and more convenient .
An Underwater Hotel
It looks like a spaceship but it is actually a picture of an underwater hotel. A company plans to build in the sea which is about 18 metres below the surface. The whole building is underwater and you can get to it by swimming and diving.
Google Glass
Google Glass is a pair of glasses with a battery hidden inside the frame(边框). It can perform many of the same tasks as smart phones. The glass has a hidden camera and a tiny screen. It is designed to take hands-free photos or videos of anything people are doing.
A New Kind of Shirt
Hate washing clothes? You're going to love this kind of shirt made by an American clothing company, Wool & Prince. This shirt can be worn for 100 straight days without washing! The Wool & Prince shirt never needs ironing(熨烫).
The Digital Library
Can you imagine walking into a library and finding all books have turned into computers? The first bookless public library is planned to open in San Antonio, Texas. Computers will take the place of books soon.
如图,ABCD为⊙O的内接四边形,E为AB上一点,∠CBE=50°,则∠AOC=( )