已知椭圆x2/a2+y2/9 与双曲线x2/4-y2/3=1
1年前2个回答
1年前3个回答
1年前1个回答
1年前3个回答
你能帮帮他们吗
精彩回答
Although he failed this time, he didn't give up and ____ studying hard.
11个月前
A: Congratulations ! Your speech for the graduation ceremony(毕业典礼)is wonderful. B: Thanks a lot.
1年前
自然界中,陆地上绿色开花植物的叶与水中浮水植物的叶(如睡莲)在结构上有什么区别?请简要说明理由.
1年前
He was born _______ May 30th, 2000.
1年前
Mike couldn't________ swimming before.
1年前