I believe the best answer is D.
All answers contribute to a machine, if there is an all above choice, chose that.
Mmncotiuy unscrambled would be Community
Less water = less weight to make it rise
More water = more weight to make it dive
All chemical reactions have a conversation of mass and energy.
Because:- There are only two laws for conversation in a chemical reaction. The conversation of mass, no mass can be created nor destroyed. Also, the law of conversation of mass states that no energy can be created nor destroyed in a chemical reaction. The charge can obviously change because they can bond and change charges.
