A:次氟酸的结构式为H﹣F﹣O
B:CH4分子的球棍模型:
C:1H,3H2,D互为同位素
D:CO2电子式
如图,平行四边形ABCD中,AB=2,AD=1,∠A=60°,点M在AB边上,且AM=13AB,则DM→·DB→等于 ( )
观赏黄果树瀑布的最佳方法是( )
Our village is holding a meeting to raise money for building the new hall.
已知抛物线y=ax2+bx+c(a≠0)经过点A(1,0),B(3,0),C(0,3).
IT'S MY BIRTHDAY
Ann hopes you can come to her birthday!
Time
Twenty to six in the afternoon
Date
Monday, July 14th
Place
Flat 9B West Wing Tower
Phone
875-4615
Note
The more friends, the better.