以下属于一类精神药品的是
A.咖啡因
B.安定
C.吗啡
D.哌替啶
E.舒乐安定
参考答案:A
Reading comprehension. 阅读理解。
Today is Thursday, December second. The weather is sunny. It is the second day of this month.
Yesterday was Wednesday December first. The weather was cloudy. Tomorrow is Friday.
1. How's the weather today?
2. What's the date today?
3. What day is tomorrow?
4. What day was yesterday?
把重10N,体积为1.2×103cm3的物体浸没在水中时,受到的浮力为______ N,当物体自由静止时,物体的状态是______(填“漂浮”.“悬浮”.“沉到水底”)