Explanation:
While My sister <em>was playing</em> the piano, my mother <em>watched </em>TV.
Gloomy
The author's tone is is gloomy as it is discussing death.
Well for a long time throughout history farming has been a way to get food. Food is essential to survival, trading, and allows them to stay in one place rather than having to travel around looking for food. How do we know that it has been important? Writings, stories, it's what we are taught in school and it is common sense that if we have it today it had to have started at some point.
Answer:
c. a poisonous gas cloud erupts
Explanation:
#Carry on learning