Why is the cell membrane said to be selectively permeable

Generally the cell membrane is like a barrier for the cell, so it doesnt allow particles in. Some particles can pass through the cell membrane (through processes like diffusion, osmosis, active transport, and cytosis), which is why it's selectively permeable: only sometimes particles can pass through the membrane.

The conclusion is that the jellyfish like the clarinet the most and the but i don’t know 25