Answer:
The movement of ions or molecules across a cell membrane into a region of higher concentration
D is the answer
It’s cell,tissue,organ, organ system
Answer:
The core concept is the sentence. The start. It's the biggest thought on the subject. There was a mistake. The author will find the principal idea in a paragraph in various ways. The principal concept is normally a phrase, and usually is the first phrase.
Explanation: detailed enough i hope
Mid-ocen ridges is correct
