Reread the second sentence in paragraph 1. What effect do the word
choices have on the meaning and tone of this paragraph?
A The phrase charged into has negative connotations and suggests
that the Forty-Niners were reckless and angry.
B The terms charged and ballooning convey the idea of sudden and
dramatic movement or growth.
c The use of ballooning gives the idea that the growth was somehow
fragile and prone to "break" suddenly or easily.
D The word unprecedented conveys the author's attitude that this
event is not well understood.

b

explanation:

  . 2 is the                                                                                                                                                      

the gas pressure p, gas volume v, and gas temperature t are given in the formula:   pv=nrt,

r is the gas constant, and n is the number of gas moles.

if the container is cooled and remains under atmospheric pressure, where r is a constant that does not change, the volume of the container remains the same, the conclusion is drawn that, with all other values ​​unchanged, the number of gas moles n, is decreases.

the right answer is a.