They put an adverti百度竞价推广ent in a newspaper looking for rock musicians.
这里 looking for musicians 作什么状语？目前分词能作目的状语吗?
目前分词，一般不作“目的状语”。有时，从语义上看上去乎是目的，那是由于目前分词的词义决定的。倘若说目前分词作目的状语，也总是带有随着性，多放于句末，且与主句用逗号隔开。现代英语一般剖析为“随着状语”。假如真的表示目的，一般用不定式，不需要目前分词。
1. Many young farmers hunted around from city to city, hoping to get good jobs.
很多年轻的农民从一个城市到另一个城市，期望得到好工作。
2. The secretary worked late into night, preparing a report for the manager.
秘书为了给经理筹备一个报告而工作到深夜。
3. She kept it a secret, trying not to lose her job.
她对此守旧秘密，尽可能别扔掉工作。
网友的这个句子，可以有两种剖析：
1. looking for rock musicians 作目的状语，逻辑主语是They：
They put an adverti百度竞价推广ent in a newspaper looking for rock musicians.
他们在报纸上登了一则广告，招聘摇滚音乐歌手。
假如真的表示目的，一般用不定式：
They put an adverti百度竞价推广ent in a newspaper to look for rock musicians.
2.looking for rock musicians 作定语，修饰adverti百度竞价推广ent：
They put an adverti百度竞价推广ent in a newspaper looking for rock musicians.
他们在报纸上登了一则招聘摇滚音乐歌手的广告。
