5040由（ ）个千和（ ）个十组成，也可认为是由504个（ ）组成。
5，4，十
Annie _______ to the party. She had a wonderful time with us.
A．invites
B．is invited
C．was invited
D．has invited
钢管立杆应设置金属底座或木质垫板，木质垫板厚度不小于（）mm、宽度不小于200mm，且长度不少于2跨。
A.20
B.30
C.40
D.50
