A:20℃时,甲、乙两种物质的溶解度相同
B:甲物质溶解度大于乙物质溶解度
C:30℃时,将40g甲物质加入50g水中,充分溶解后溶液的质量为90g
D:将20℃时两种饱和溶液升温至30℃,溶液中溶质的质量分数都增大
跑或者跳时,人的呼吸次数比休息时( )。
结合所学知识回答下列问题;
4.6×0.99=____×____-____×____
4.6×0.99=4.6×1-4.6×0.01
Many students take the school bus to school every day. Parents think taking the school bus is usually safe (安全的), but sometimes it is dangerous. Some students don't keep the school bus rules. What are the school bus rules?
Arrive at the bus station early.
Wait for (等候) the school bus at the bus station.
Don't run at the bus station.
Don't walk or fight on the bus.
Don't get off (下车) the bus when it goes.