It is true that earth is consist of 70% water. However it is still a problem that in the near future, their might be a water shortage that will happened. This is because now mostly of our water sources are no longer clean. Our water are polluted and when time will come water will be very pricey
The amount of water on the planet is fixed; it neither increases or decreases. Glaciers are sheets of moving ice. This water to form these extensive sheets must come from somewhere. The water comes from the most extensive store on the planet; the oceans. Ice Ages always corresponds to periods of low sea level because much of the ocean water is is land locked as glaciers.
Options for the question have not been given. They are as follows:
type of soil
type of plants
exposure to sunlight
method for measuring the growth
Answer:
exposure to sunlight
Explanation:
A scientific experiment has an experimental group and a control group. Control group is included to omit any error in results due to the factors other than the variable factor. Experimental group is the one exposed to different levels of the variable factor.
Here, Carlo wants to determine the the effect of day length on plants' growth. The test variable here is thus the duration of sunlight. In experimental group, this duration will be changed to determine its effect. In control group it will be kept constant so that results from other factors can be excluded from the observed experimental result.
