关于第一个问题，需要给纠正一下：并非从属连词引导的从句，都可以放在主句之前或之后。

▲ 一般说来，从属连词引导的时间状语从句、原因状语从句、条件状语从句、让步状语从句，放在主句之前或之后均可。

（例句略）

▲ 对于目的状语从句、结果状语从句、方式状语从句、比较状语从句而言，一般放在主句之后。例如：

1. 目的状语从句：

I hurried through my work so that I could be in time for wonderful TV programmes. 我匆匆地完成了我的作业以便能够赶上精彩的电视节目。

I'll speak slowly so that you can understand me. 我会说得慢些，以便你能明白我的意思。

2. 结果状语从句：

The text was so boring that I gave up reading it half way through. 这篇课文真没趣，我读到一半便放弃了。

This was such fine music that it was worth listening to twice. 这音乐太好了，值得听两遍。

3. 方式状语从句

The injured man acted as if nothing had happened to him. 这个受伤的男子行动起来好像什么都没发生似的。

Will you please do the experiment as/like I am doing? 请按我做的方法做这个实验好吗？

She doesn't speak the way he does. 她说话的方式与他不同。

4. 比较状语从句

He speaks English as well as you do. 他英语说得和你一样好。

He was more successful than we had expected. 他比我们想象的要成功得多。

▲ 对于地点状语从句，可分两种情况：如果主句谓语动词是不及物动词，地点状语从句一般紧挨着动词，这就像He lives in this city.一样，我们不说In this city he lives. 也就是说，这时地点从句放在主句之后。否则，如果句子结构比较松散，那么从句在主句前后均可。

1. 从句放在主句后：

We live where the road crosses the river. 我们住在河流与街道交叉的地方。

You can go anywhere you like. 你可以到你想去的任何地方。

2. 从句在主句前后均可：

We’ll have a chat where there is not much noise.

Where there is not much noise, we’ll have a chat.

我们要在一个不那么吵闹的地方谈心。

You’d better make marks where you have questions.

Where you have questions, you’d better make marks.

在你有问题的地方最好做出标记。