如图所示血液分层实验,错误的是( )
A:①是抗凝剂
B:②是血浆
C:③是白细胞
D:④是红细胞
在某幼儿园的美术课上,老师带领小朋友用水彩笔为本子上两个大小不同的气球涂色,要求一个气球只涂一种颜色,两个气球分别涂不同的颜色.小朋友豆豆可用的有暖色系水彩笔红色、橙色各一支,冷色系水彩笔绿色、蓝色、紫色各一支.
(1)豆豆从他可用的五支水彩笔中随机取出两支按老师要求给气球涂色,求两个气球同为冷色的概率.
(2)一般情况下,老师发出开始指令到涂色活动全部结束需要10分钟,豆豆至少需要2分钟完成该项任务.老师发出开始指令1分钟后随时可能来到豆豆身边查看涂色情况.求当老师来到豆豆身边时,豆豆已经完成任务的概率.
饭后散步已成为我们生活中最普及的一种运动,请根据以下提示,写一篇80词左右的文章.
1 When and where do you usually do it?
2 How often do you do it?
3 How long do you do it each time?
4 How does it help you keep fit?
根据材料内容,选择正确答案。
I live in a small town near Xing'an in Guilin. You can't see it on the map of China, because it is too small. The air here is fresh(清新的). There are not many tall buildings in our town. The tallest building is in our school. There are four hundred students and twenty-five teachers in our school. In the front of the school, there is a playground. I often play basketball with my classmates on it. There is a little garden behind our school. And we can grow(种植) beautiful flowers and plant trees there. Next to the garden, there is an orange orchard(果园). You can hear birds singing everywhere. There is a river not far from our school. In summer, we usually go swimming with our teachers in it. We study Chinese, English, Maths and other subjects at school. The teachers are very nice. We love our school.