A:一个
B:三个
C:5个
Name
Peter
Age
13
Nationality
American
Appearance(外貌)
Medium height, short blonde hair, wear glasses
Hobbies
Read books, play chess
Favorite food
Beef and carrot noodles, vegetable salad
Personality(个性)
·smart (learn well)
·friendly and popular(help others)
已知椭圆C: x2a2+y2b2=1(a>b>0) 的离心率为 22 ,焦距为2,直线y=kx(x≠0)与椭圆C交于A,B两点,M为其右准线与x轴的交点,直线AM,BM分别与椭圆C交于A1,B1两点,记直线A1B1的斜率为k1
人生活在自然界中,就像鱼生活在____,人与自然界的关系就像____的关系。