The particles that can pass through a semipermeable membrane are the ones found in:
A) Solutions
B) Suspensions
C) Colloids

Option B. Suspension.

Explanation:

The particles that can pass through a semipermeable membrane are the ones found in suspension because in solution the solute are tightly attached with the solvent while in suspension the solute particles remain suspended and easily be pass through the semi-permeable membrane. The particles of colloid are large in size which cannot pass through semi-permeable membrane.

r just means there's a number of carbon in teh chain. for example rcooh means that after x number of carbon, the chain ends with cooh.

explanation:

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.