Answer:
Viruses can be both useful and harmful because some viruses make you sick, while others can fight against more dangerous viruses.
If there are choices please give them to me. But I would say that they are able to test different layers of glaciers in the polar ice and measure the constancies of carbon and temperature.
There were more dark moths around factories because trees were darker near factories because of pollution. More light moths were found in the country away from the factories, in the forests with no factory pollution
When energy passes from one trophic level to the next, I would guess that the two factors which decrease the total amount of energy from being passed up are:
1. An organism does not assimilate all the energy of food consumed. Within a consumer, digestion and assimilation of energy is not 100% efficient: some of the energy is lost.
2. A large proportion of energy assimilated by a producer and consumer is lost through respiration, i.e., day-to-day maintenance of metabolic processes.
Answer:
hydrogen, oxygen, carbon and nitrogen
I did 4 instead :')
Explanation: