The word 來 (lái) can be used to connect two verb phrases, relating the actions to each other in Chinese grammar. It can be translated as "in order to" or "so that" and it can help in explaining reasoning.
Connecting two verb phrases is very easy. All you need to do is to place 來 in between them. This has the meaning of doing the first verb to achieve the second verb. Often used with words expressing a way or a method, e.g. "通過""用"(tōngguò/yòng).
通過/用 + Verb phrase 1 + 來 + Verb phrase 2
1.Xiǎnrán nǐ xūyào gèngduōshíjiān lái zhǔnbèikǎoshì.
顯然 你需要 更多時間 來 準備考試。
It's obvious that you need more time to prepare the exam.
2.Tāmen tóngyì tōngguò tánpàn lái jiějué wèntí.
They agreed to solve the problem by negotiation.
3.Tā zhǐ néng yòng zhègelǐyóu lái ānwèi zìjǐ.
她 只 能 用 這個理由 來 安慰 自己。
She can only console herself with this reason.
4.Xiànzài huàn wǒ lái wèn nǐ yīgewèntí ba.
現在 換 我 來 問 你一個問題 吧。
Now let me ask you a question, for a change.