A:乙炔(C2H2)和苯(C6H6)
B:乙醇和丙醇(CH3CH2CH2OH)
C:乙醇和乙醚(C2H5OC2H5)
D:甲烷和乙酸
王教授日记中这样写道:“这里的大多数植物的叶子坚硬,叶面光滑且有蜡质薄膜,果园里种植的大多是柑橘、柠檬、无花果和葡萄。”据此回答下列各题:
已知方程mx+ny=10,有两个解分别是x=-1y=2和x=2y=-1,求m﹣n的值.
听短文完成表格。
My friend Cindy
Where does Cindy live?
She lives____.
What is Cindy fike?
She is____.
What does Cindy do on weekends?
She____with her mother.
What's Cindy good at?
She is good at____.
What does Cindy do after school?
She always____with me.