A:加速度增大
B:加速度减小
C:速度增大
D:速度减小
Tomorrow we will go to Hainan. It's warm there. We will have a special Chinese New Year's Day. Now let's get ready! We need three tickets from Shijiazhuang to Hainan. We don't need winter clothes. I want a beautiful dress. My parents take some T-shirts and shorts. We need to take milk, cakes and fruit. We need three hats. The sun is very hot there. We don't want to turn black. That's all done.
① ② ③ ④
⑤ ⑥ ⑦ ⑧
⑨ ⑩ ⑪ ⑫
____
贫血是指( )
一轻质弹簧弹力F和弹簧长度l大小的关系如图所示.求: