检验检疫机构签发的产地证书是进口国海关征收或减免关税的有效证明。( )
参考答案：对
My friend John called and ____me to his party just now.
A．will invite
B．invited
C．invites
D．has invited
机体内最多的铁是（）
A.血红蛋白铁
B.贮存铁
C.组织内铁
D.转运铁
E.游离铁
