-- Could you tell me __________ yesterday?
-- Because my bike was broken on my way here.
A:why you came late
B:why do you come late
C:why you come late
D:why did you come late
如图,直线a,b都与直线c相交,给出的下列条件:①∠1=∠7;②∠3=∠5;③∠1+∠8=180°;④∠3=∠6.其中能判断a∥b的是( )
要使二次根式x-1有意义,字母x的取值范围必须满足的条件是 ( )