They ____ (be) young, now they ____ (be) old.

执行如图程序框图，如果输入的a=4，b=6，那么输出的n=（　　）

选择方框内的单词，并用其适当的形式填入空白处，使内容意思通顺，语法正确。

    Linda is from ____. She is thirteen. Her sister's name is Sally. She is only five ____ old. Linda is in No.2 Middle School. She is a good student. She ____ beautiful eyes. They are big and black. She is a good football player. Her ____ star is David Beckham(大卫·贝克汉姆). Her father is a teacher. Her mother is a teacher, ____. They have a big house and a car. She has a happy family(家庭).

若一次函数y=（m+2）x+（m²﹣4）经过坐标原点，则m=____．