Answer:
Standardisation is used to determine the concentration of a volumetric solution in order to achieve accurate and reliable titration results
Hope u do well :) ik this maybe hard but you’ll get through it , the answer is D !
It's called simple diffusion, the small molecules without charges such as oxygen and carbon dioxide can flow through a plasma membrane without assistance and without expending energy. Other substances such as proteins, glucose and charged particles called ions cannot pass through the selectively permeable membrane.