'Thus' in the Bible

Thus I considered all my activities which my hands had done and the labor which I had exerted, and behold all was vanity and striving after wind and there was no profit under the sun.

Thus I hated all the fruit of my labor for which I had labored under the sun, for I must leave it to the man who will come after me.

This also is a grievous evil—exactly as a man is born, thus will he die. So what is the advantage to him who toils for the wind?

So then, I have seen the wicked buried, those who used to go in and out from the holy place, and they are soon forgotten in the city where they did thus. This too is futility.