There was a time ______ I thought my dad didn't know a thing about being a good father.
A：when
B：which
C：that
D：what
— Whose cap is this?
— It's .（ ）
The magazines are _______ easy that the children can read them well.
斜率为1的直线经过抛物线y2=4x的焦点，与抛物线相交于A，B两点，则|AB|=____
