悬浮在水中的潜水艇排出水舱中的一部分水后,潜水艇将( )
A:下沉
B:上浮
C:仍悬浮在水中
D:先下沉后上浮
A:Our new school is big and nice. There is a gym in our school now.
B:Yes, and there is a big library, too.
造血干细胞移植是白血病等某些血液病患者治愈的唯一希望,人的造血干细胞产生血细胞的过程在生物学上称为( )
Many teenagers feel that the most important people in their lives are their friends.They believe that their family members don’t know them as well as their friends do.In large families,it is quite often for brothers and sisters to fight with each other and then they can only go to their friends for some ideas. It is very important for teenagers to have one good friend or a group of friends.Even when they are not with their friends,they usually spend a lot of time talking among themselves on the phone.This communication is very important in children’s growing up,because friends can discuss something.These things are difficult to tell their family members. However,parents often try to choose their children’s friends for them.Some parents may even stop their children from meeting their good friends.Have you ever thought of the following questions? Who chooses your friends? Do you choose your friends or your friends choose you? Have you got a good friend your parents don’t like? Your answers are welcome.