It's often impossible to repeat trials on the same subjects. 2-Subjects may report an inaccurate medical history. 3-It can be difficult to control all possible variables. 4-It's impossible to come up with testable scientific questions for human subjects.
The answer is (D). Creating more fossil fuels.
Fossil fuels are formed by the compression of the dead matter of plants and animals within the crust of the Earth. The plants and animals that died due to some calamity millions of years ago got covered by the rocks and soil. The internal heat of the Earth and the pressure due to the weight of the rocks turned them into thick dark crude oil. This process is natural and time consuming. It is impossible to recreate this process by artificial means on a large scale to make more solid fuels.
Interestingly, mining of extra-terrestrial planets, moons and asteroids is an ongoing research and the means to do it are being prototypes in the research laboratories of NASA and other space organisations.
je ne comprends pas ton questiom
Answer: B
Explanation:
Honestly, I would say a word. Since it states that codons are read by mRNA molecules in groups of three, they could be easily compared to words, not letters.
Your answer is Adenosine diphosphate (ADP)