数词+hundred/thousand/million/billion+名词复数
hundreds/thousands/millions/billionsof+名词复数
例1
1.＿＿peoplegoswimminginsummerinDalian.
A、ThousandsB、Thousand ofC、Thousands of D、Thousand
2.＿＿the students will take part in this English speechcon test.
A.Two hundred of B.Two hundreds of C.Hundreds ofD.Hundred of