ⅰ.用所给词的适当形式填空
1．steel is a mixture (mix) of iron and other s ubstances.[:]
2．we can surely draw a conclusion (c onclude) f rom our discussion.
3．he needed help to set up the equipment (equip)．
4．the audience reacted (reaction) coldly to his speech.
5．the economy has contracted (contract) by 2.5% since last year.
6．he said that these
