Which of the following is a way that advancements in technology improve humans' ability to measure air quality and protect human health?

Answer( solar wind );

Largely uneconomic because they provide little profit or food surplusi think so

Just try your best buddy

It's either  a. chiang kai-shek and the nationalists turned against the communists and killed hundreds of them. orb. hundreds of peasants were killed in shanghai during the period of warlord rule.  if we take into account that there was warlord rule at the time, i think that it's b (not entirely sure though)just my best thoughts.