下图是a、b、c三种物质的溶解度曲线,下列说法正确的是( )
A:a物质的溶解度一定小于b的溶解度
B:40℃时,a、b两种物质的饱和溶液中溶质的质量分数相同
C:c物质是一定是二氧化碳溶解度曲线
D:三种物质的饱和溶液分别从40℃降温到20℃,a、b 析出的晶体质量相等
Hi! This is Mr. Li's farm. Let's have a look. There is a vegetable garden. These are carrots and pumpkins. Those are tomatoes and green beans over there. There are animals, too. What's that? It's a cow. How many cows on the farm? He has ten cows on the farm.
根据上面短文的意思判断下面的句子是否正确。
— Tomorrow we'll have an English exam. I'm worried about it.
— _______ You will do better.
G20峰会给杭州带来了打造国际化城市的重大机遇。市委市政府提出杭州要大力提升对外贸易核心竞争力,支持重点企业“走出去”。该举措的背景有( )
①经济全球化的迅猛发展 ②世界经济技术的发展规律
③“走出去”是杭州发展的根本基点 ④对外开放是我国的基本国策