下列溶液有时呈黄色,其中由于久置时被空气中氧气氧化而变色的是( )
A:浓硝酸
B:硫酸亚铁
C:高锰酸钾
D:工业盐酸
东北土地辽阔而气候寒冷,为更多接纳阳光,院子常十分宽大,宅墙内空地甚多,北京四合院,庭院方正,是为冬季多纳阳光;冀南和晋、陕、豫等地,夏季西晒严重,院子变成南北窄长,利用西厢减少东厢的西晒;西北甘、青一带,风沙很大,院墙加高,称为“庄窠”。这些特点体现了( )
①中华文化在继承中积累而成
②一方水土,一方文化
③我国各地文化的差异性
④文化遗产对研究文明演进的意义
下列说法正确的是( )
A
Fascinating Plant Show
All kinds of plants from all over the world will surprise you!
Time: 8:00 am—6:00 pm, May 1st—May 10th
Ticket price: ¥10
Place: People's Park
Traffic: No.1 Bus, No.10 Bus, No.12 Bus
Welcome to the Biggest Gardening Club!
Do you like gardening? Do you want to learn how to plant flowers? Please come to the Gardening Club.
Time: 10:00 am—4:30 pm, Wednesday—Sunday
Tel: 15831777899
Mr. Mango's Fruit Store Sale
We have all kinds of fresh fruits on sale. Do you like apples? We have red apples for only ¥2/kilo. We also have mangoes(芒果) for¥6/kilo, watermelons for¥1/kilo and pears for ¥2/kilo. Come and see by yourself.
Time: 8:00 am—8:00 pm
Hotline: 5684764
观察洋葱表皮细胞时视野中出现如图所示的现象,则最可能出错的步骤是( )