Why is a standard system of measurement important?
a.
scientists want to share measurement data that they can understand.

b.
each country wants its own set of measurement standards.

c.
measurements are seldom shared with scientists in different countries.

d.
scientists speak many different languages.

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.

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".