∵①12a=23a，③3a2=a3，
∴①⑤是同类二次根式．
The Parkers bought a new house but ______ will need a lot of work before they can move in.
A．they
B．it
C．one
D．which
自然灾害或意外事故以外的原因造成的存货毁损所发生的挣损失，均应计入管理费用。 ( )
