The Earth has ________ for the past 2 million years.
A) stayed the same temperature
B) slowly frozen then quickly thawed
C) gradually cooled
D) gradually warmed
E) cycled between hot and cold
Question 2
Which of the following practices will help reduce greenhouse gas emissions?
A) using renewable energy sources
B) using technologies that increase carbon in the environment
C) reducing energy efficiency
D) using nonrenewable energy sources
E) using technologies that capture carbon for later release into the atmosphere