This is correct. Even the basic scientific theories get tested and checked time after time after time. The most basic example would be that people once thought the Earth was flat and now it changed and they believe it is round.
D. The mantle is the densest part
Answer: The Paraphrase means that the one who is elected to preside over the House of Representatives should remain impartial and unbiased while deciding on the matters that are floored in the House. He should permit what the ruling party seeks to do by ratifying and validating their actions, or by passing the legislations that are sought to be passed by the majority party.
Explanation: It is expected that the Speaker of the House of Representatives goes by the inclination of the majority party and allows them to function to achieve their legislative goals. The will of the majority party ultimately serves as the will of the majority people of the nation because the mandate they have is given by the people. Thus, it is necessary for the Speaker to ratify the will of the majority party.
Based on the information I was able to find I would say "Natural gases".
This is due to the reason it is burned to create heat for buildings which are used for several things we do daily such as cooking, heating, and electricity.
Miss something important such as taxes