many factories may have to close down.这里为什么要用主动表被动?为什么不能说to be closed down?

many factories may have to close down.这里为什么要用主动表被动?为什么不能说to be closed down? Why aren't there many factories like the Symi factory? factories/many/release/water/into/rivers/dirty连词成句 （ ） so many cars ,there are many factories too.填上一个适当的介词使句意完整. “how many”后面加什么?How many后面加“factory”还是“factories”? You may use my bike There aren't any factories in the city. as many of you may How many birthdays in May? why are't there many factories like the Simi factory.怎样翻译 there is not much p_____in the small town because there are not many factories 1.The old man is very rich.He o many supermarkets and factories. （连词成句）题目：many,cars,factories,are,in,now,there,Shenzhen,shops,and Are there many factories in shenzhen 50 years ago no,there are not,改错误快 are there many factories in shenzhen 50 years ago?这句话错在哪里? Many factories ______ during the economic recession.A.closed downB.put downC.went downD.knocked down they are many ______in the factoriesthey are many e_____in the factories （根据所给的首字母,完成句子） factories variants May many fortunes find their way to