A:
B:
C:
A:Good morning.
B:____
A:I am Li Fei.____
B:My name is Wang Qiang.
A:____
B:Yes,I am.
A:I am twelve.____
B:I am twelve too.
B:OK! Let's go.
A.Good idea!
B.How are you?
C.Good morning.
D.What about you?
E.What's your name?
F.Are you from Beijing?
G.Let's go and play football.
在正四面体P-ABC(所有棱长都相等)中,D,E,F分别是AB,BC,CA的中点,下面四个结论中不成立的是( )
如图,放在水平面上的容器中装有500g水,容器重力为3N,水面h1高为8cm,容器高h2为15cm,容器底面积为40cm2,求:水对容器底的压力和容器对水平面的压强?