معنى فاعلية

Sure. Pus in the spinal canal makes it hurt to move your head up and down,

The most effective way to deliver the drug is right into his brain via the spine.

We're gonna start you on thyroxine. It'll make you feel better and level your moods.

Working in this clinic obviously instills a deep sense of compassion.

I did. You gotta talk to her. I couldn't bear it if something happened to her.

I did what you do all the time. The only difference is, I did it to you.