Answer:
The correct answer is - Sustainable development.
Explanation:
Sustainable development is the process of using or utilizing the natural resources in the present in such an efficient way that there will be resources for future generations without compromising their needs.
It is essential in the current situation as people overexploiting the natural resources that it is quite possible there will very few resources will be left for future generations.
The correct option is D.
A virus refers to an infectious micro organism that is made up of nucleic acid molecule that is enclosed within a protein coat. Viruses are only able to reproduce and multiply when they come in contact with living cells, in the absence of living cells they remain dormant and they do not show any sign of been a living thing. The nuclei acid molecule of a virus can be in form of a DNA molecule or a RNA molecule.
Integral proteins are embedded in the phospholipid layer, and can sometimes form protein channels that let ions and other small molecules through.
question 12 part a is hydrogen bonds
and 13 is because helium is a noble gas
hope it helps