Looking to do a zoo m call

Which pronoun has an unclear antecedent in the following sentences? the sixth-grade students liked volunteering their time to read to the elderly people in the hospital. it made them happy. a. their b. it c. them d. no unclear antecedents

As our current atmosphere formed, the concentrations of various atmospheric gases fluctuated. match each gas with the explanation that best describes how its proportion changed during the evolution of the atmosphere.

35 points pls fast. in a citizens elect the president as head of government separately from the legislature. question 1 options: parliamentary democracy communist state presidential democracy autocratic state question 2 (1 point) this form of government has only a single political party. question 2 options: communist democratic autocratic parliamentary question 3 (1 point) this is a government controlled by one person with absolute power. question 3 options: communist democratic autocratic parliamentary question 4 (1 point) a government is a government system where all citizens that choose to vote have a say in their government. question 4 options: communist democratic autocratic theocracy question 5 (1 point) in a the people elect the legislature, and the legislature chooses the head of government. question 5 options: parliamentary democracy communist state presidential democracy autocratic state