He does nothing, just like a good-for-nothing big tree.

She is beautiful like a flower.

This flower is as beautiful as a plum blossom.

This flower is very beautiful.

He is feigning ignorance about that problem.

It's better for him not to know the truth. After all, ignorance is bliss.

He knows that pain through his own experience.

He is working hard to make his abilities known to the world.

God only knows what he is thinking.

I have no way of knowing what he is thinking.