Which definition is the best for “semipermeable membrane”?

A membrane that lets a select few things through, while keeping other things out.

Explanation:

Permeable means "letting things pass through", so semipermeable means that it lets only some things pass through, and not all.

one is through turgidity. this occurs before ground tissue ( collenchyma

and sclerenchyma cells) become well

developed to give structural support to the plant as it grows bigger. the xylem

tissue (composed of rigid tissue) of the young

plant render this support and also maintaining osmotic turgidity of the surrounding

plant cells.

carbon atoms, hydrogen, oxygen, and nitrogen.