Every minute is made full _______ of _______ our lessons well.

A．to use; study

B．use; studying

C．use; to study

D．used; studying

下列反应中铁元素发生氧化反应的是

A．FeS+2HCl=FeCl₂+H₂S↑

B．Fe+H₂SO₄=FeSO₄+ H₂↑

C．Fe₂O₃+3CO2Fe+3CO₂

D．2FeCl₃+Cu=2FeCl₂+CuCl₂