不用接,因为是how引导的从句,做方式状语,how to do sth：怎样去做某事.为什么how to do it 中it不能去掉呢？it指代前面说的那件事啊，如果把it去掉，那就是错误的句子啦。举个例:Could you please tell me how to speak the word?=Could you please tell me how to speak itit就是指代的the word（单词）。