In order to conduct a research you should have an dependent variable, independent variable and the control variable. so in order to study phototropism, then you should need sun light and the growth of the plant and you must have a control that why you need a dark room.
The answer I would say is A.
The sun doesn’t make water
And electricity doesn’t come from the water cycle.
Answer:
In addition to storing water, the reservoirs behind each of these 500 barriers also trap sand that used to be carried to the shoreline. Dams now withhold sediment from about 16,000 square miles of the state's coastal watersheds and have reduced the flow of sand by 25%, or about 3.6 million cubic yards each year.
Explanation:
To slow the process of bacteria growth
Answer:
To prevent or limit bacterial contamination of the collected blood
Explanation:
The first few milliliters of blood have been reported to have a high probability of bacterial contaminant from the skin. Several studies have shown that diverting the first 10 to 30 milliliters of blood from a donor into a special pouch is effective in limiting the chances of collected blood being contaminated with bacteria.
<em>Hence, the purpose of the procedure is to limit the bacterial contaminant that will enter the blood collection bag.</em>
