lead in 后面需要加to使用吗？   lead in与lead into 有区别吗？

Sometimes we even need to spend time leading in to a request .(九年级教材原句)   

lead in 后面必须加to吗？

lead in to sth=引入到某个事情上面

上句的同义句可以是

Sometimes we even need to spend time leading into a request .   

这个作为同义句对吗？

求老师解答，谢谢！

回答如下：

lead into 

(1)把…带入 

He led us into the room. 

他把我们引入室内。 

The horses were led into the yard. 

马被牵进了院子里。 

(2)导致 

His careless spending led him into debt. 

他随便花钱使他负债。 

Behavior like this will lead you into trouble. 

这样的行为会给你惹麻烦的。 

(3)(道路等)通向 

This passage leads into the courtyard. 

这条路通向院子。 

Gutters lead the water into the ditch. 

排水沟把水排到这条水沟里。

lead on to 引起，导致

(1)导致；引致

It is often the case that early interests lead on to a career.

职业生涯往往由早期爱好而来。

This discovery led on to studies of the immune system. 

此发现使人们开始对免疫系统进行研究。

(2)通连；通到；通往

There were glass doors leading on to this balcony. 

有玻璃门通到这个阳台。

lead to 

(1)把…带到, 领到 

The bell-boy led us to our rooms. 

旅馆服务员把我们带到了我们的房间。 

(2)(道路)通向 

All roads lead to Rome. 

条条道路通罗马。 

(3)导致, 引起 

In given conditions, a bad thing can lead to good results. 

在一定条件下, 一件坏事可以导致好的结果。 

An ordinary cold can soon lead to a fever. 

一场普通的感冒很快便会引起高烧。 

lead up to

(1)（一系列事件）导致，致使，引致

Alan Tomlinson has reconstructed the events that led up to the deaths... 艾伦·汤姆林森再现了导致多人死亡的一系列事件。

They had a series of arguments, leading up to a decision to separate.

他们经过连番争吵后决定分居。

(2)（时间）临近，紧挨在…之前

the weeks leading up to Christmas.

圣诞节前的几个星期

(3)（把谈话）引向（某个话题）

I'm leading up to something quite important.

我正要谈到相当重要的部分

lead on劝诱，哄骗；带领…继续前进；走在前面

(1)怂恿；教唆；鼓动

I bet she led him on — but how could he be so weak?

我看他一定是给她唆使的——可他怎么这么容易受人影响？