丁丁家到学校相距550米,今天他上学走了8分钟,他每分钟大约走多少米?
550÷8≈70(米);
答:他每分钟大约走70米.
读一读,重新排序,使对话通顺。
A. I'm going to the baker's.
B. Yes, we are going to sing and dance all night.
C. I'm going to buy a birthday cake. Today is my birthday.
D. Hi, Jim. Where are you going?
E. What are you going to buy?
F. Happy birthday! Are you going to have a birthday party?
G. Good idea. When are you going to have it?
H. At 6 o'clock. Welcome to join us.
正确的顺序是: ______________________________________________________
(3分)下图为甲、乙、丙三种物质的溶解度曲线,据图回答:
(1)要提纯含有少量乙的甲物质,通常采用的方法是
________________________________________________________________________。
(2)t1℃时将等质量三种物质的饱和溶液,升温至t3℃时,其溶液的质量关系为________________________________________________________________________。
(3)将20克甲物质完全溶解于100克水中,不能形成饱和溶液的温度范围是________℃。