原式=(23)2-(5)2
=12-5
=7．
故答案为7．
–Whose advice do you think I should take?
–______.
A．You speak
B．That's it
C．It's up to you
D．You got it
支搭跨越架的目的是保护线材免于（）。
A、车压
B、磨损
C、人踩
