基本接近我们今天对宇宙认识的天学理论是（）。
A.盖天说
B.浑天说
C.宣夜说
D.五行说
参考答案：C
Many boys in our class _____ the school singing competition and some of them got the prizes. [ ]
A. join
B. joined
C. took part in
D. take part in
具有促进铁吸收功能的是( )
A．维生素A
B．维生素B1
C．维生素C
D．维生素D
