问题
选择题
下列关于细胞分化的叙述，正确的是（ ）
A．细胞分化的结果形成不同的组织
B．细胞分化的结果是细胞数目增多
C．细胞分化的结果直接形成各种器官
D．细胞分化的结果是细胞的体积增大
答案
答案：A
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下列关于细胞分化的叙述，正确的是（ ）
A．细胞分化的结果形成不同的组织
B．细胞分化的结果是细胞数目增多
C．细胞分化的结果直接形成各种器官
D．细胞分化的结果是细胞的体积增大
答案：A
It’s reported that school accidents, such as food poisoning (食物中毒), fires, electricity and traffic, kill more primary and middle school students than anything else. So we must learn how to protect ourselves better. Here are some tips for keeping safety in mind every day.
On our way home or to school: Wait for the green traffic light, and look left and right before we cross the road. We’d better wear bright-color clothes, so the drivers can see us easily. Don’t believe strange people in the street.
At school: When students around us begin to push each other, we need to stand still and try to hold onto something, or stay in a corner until the crowd leaves. If we fall down in a moving crowd, use both hands to cover the head. Lean to one side, curl up (蜷缩) our body and bend (使弯曲) the legs.
In a fire: Stay calm. Leave the classroom quickly under the directions of the teachers. Smoke can be more dangerous than fire, so use a piece of cloth to cover our mouth and nose. What will we do if the clothes burn? Remember not to run! Drop and fall to the ground. Then roll! It will make the fire go out.
For eating: Wash fruits carefully before eating them. Check the expiration dates (保质期) on the packages of the snacks, and if it looks or smells bad, don’t eat it.
| Topic: Keep 小题1: in mind every day | ||
| Fact | It’s 小题2: that school accidents kill more students than anything else. | |
| Safety Tips | On the 小题3: | Wait for the green light, look both sides before we 小题4: the road. Wear bright colors. Don’t believe strangers in the street. |
| At school | It’s 小题5: for us to stand still and try to hold onto something, or stay in a corner until the crowd leaves. We’d better cover our head with both hands, leaning to one side, curling up our body and 小题6: our legs. | |
| In a fire | Stay calm. Follow the teachers’ 小题7: and leave quickly. Cover our mouth and nose 小题8: a piece of cloth. Drop to the ground and roll over and over to put out the fire. | |
| For eating | Wash fruits carefully before we eat them. Check the expiration dates. Don’t eat the food that 小题9: bad. | |
| Purpose | To make the students know the tips to be protected from 小题10: . | |