Answer:
<em>Option "A" might be the correct answer</em>
<em>Explanation:</em>
<em>there are some of those viruses where it can be quite potent. Some viruses, such as the rhinoviruses, seldom cause serious illness. But others, such as parainfluenza and respiratory syncytial virus, can lead to severe lung infections in young children.</em>
Key is to lock as D. Substrate is to active site.
Oil is an example for being such a low density to float on water
A balance that performs in an enclosed compartment with no air currents to disturb is called an analytical balance.
Analytical balances are instruments used for precise and determination of mass of matter. They are accurate and very precise instruments. They require a draft-free location on a solid bench that is free of vibrations.
Analytical balances of today are digital and have built in calibration weights to maintain accuracy. Older versions usually require to be manually calibrated using specific standard weights.
D. it serves as a link between membrane proteins on adjacent membranes.