A:NaOH
B:NaHCO3
C:H2SO4
D:K2SO4
李庆新在《海上丝绸之路》中写到:“唐朝与海外发生官方关系的国家和地区有70余个”。由此可见,唐代对外交往比较活跃。出现这一局面的原因是( )
①国家统一、社会安定 ②政府鼓励各国商人到中国贸易 ③经济繁荣、文化辉煌 ④对外交通发达
阅读理解,判断正误。
I'm Lily. I like animals.Look! This is a panda. It's fat. It has two black eyes. But that rabbit has two red eyes. I have a cat. It has two green eyes. I have blue eyes.
读“北京,武汉,广州,哈尔滨四个城市的气温曲线和降水柱状图”并完成.
我国南极考察队由上海出发到我国的南极考察站﹣﹣中山站(69°S,76°E),途经地球五带中的( )个.