there are only a few steps to doing the experiment 为什么不用to do,而用 to doing
问题描述：
there are only a few steps to doing the experiment 为什么不用to do,而用 to doing
答
因为后面的to doing the experiment
是前面steps的定语
并且此地to是介词,不是动词不定式,所以用to doing.
类似的还有,the key to the door,the answer to the question,to都是介词.