If it comes to a showdown, do you think you will be confident enough todefeat them？
此处的come to的意思是，什么使用方法？谢谢老师!
it comes to 看作习语。常常用于时间从句或条件从句（如网友的例句）。意为：涉及到；谈到；说到；假如到了...的时候。作为习语记忆即可。这里 it 是虚拟主语，仅充当主语用途，没实质词语意义。
If it comes to ashowdown, do you think you will be confident enough to defeat them? 假如要决战（决赛），你觉得你有足够的信心打败他们吗？
If it comes to thepush, we shall have to use our savings.
遇有急用时，大家只好动用积蓄。
She's veryingenious when it comes to finding excuses.
她非常擅长找借口。
《牛津词典》
When it comes togetting off work, he knows all the dodges.
说到请假歇班，他什么花招都想得出。
《牛津词典》
When it comes toexpressing himself he is no shrinking violet.
他表达自己怎么看时一点都不羞怯。
《柯林斯英汉双解大词典》
She's nobody'sfool when it comes to dealing with difficult patients.
她应对难缠的患者非常有方法。
《牛津词典》
When it comes TOPollution, the chemical industry is a major offender.
谈到环境污染问题，化工产业是一大祸害。
《牛津词典》
Your languageswill stand you in good stead when it comes to finding a job.
你通几种语言，找工作时就会显出优势。
《牛津词典》
Sometimes smallfirms can outdo big business when it comes to customer care.
在客户服务方面，有时小企业可能优于大企业。
《牛津词典》
These workers arefed up with being at the bottom of the pile when it comes to pay.
这类工人受够了收入水平处于底层的烦恼。
《柯林斯英汉双解大词典》
When it comes tododging disaster, the champions of the insect world have to be cockroaches.
谈到躲避灾难，昆虫界的冠军非蟑螂莫属。
《柯林斯英汉双解大词典》
