—A one-way ticket $40, and you can another $20 for a round-ticket.
A:costs; pay
B:cost; spend
C:pay; spend
D:spends; pay
买一个足球需要m元,买一个篮球需要n元,则买4个足球,7个篮球共需要( )元
△ABC的内角A,B,C的对边分别为a,b,c,已知△ABC的面积为 a23sinA .(12分)
Don't do any other things while you are doing your homework. So please _________ your MP3.