题干
连线。
①Can your father play football? ____ A. Yes, she can.
②Can she ride a bike? ____ B. Here you are.
③Here's a card for you. Happy Teachers' Day! ____ C. No, he can't.
④Give me a balloon, please. ____ D. Thank you.
答案(点此获取答案解析）
C,A,D,B
（x＞0），y= 
（x＜0）的图象上的点，且，∠AOB=90°，则 
的值为（ ） 