How do you use the word vane vain and vein in a sentences with an adverb?

Here are some sentences using the words "vane," "vain," and "vein" with adverbs:

* Vane: The weather constantly shifted the wind vane, making it difficult to determine the direction.

* Vain: She proudly displayed her new necklace, but her efforts to impress were completely vain.

* Vein: The doctor carefully examined the patient's vein, searching for a suitable spot to insert the needle.