<span>The question says,'decomposition of plants and animal matter present in the soil is largely due to soil micro organism. The statement is true. The soil microbes function by decomposing the organic matter in the soil to the forms usable to plants. The humus produce by these microbes is largely responsible for soil fertility. </span>
The correct terms to fill in the blanks would be contracts and dilates. In stressful situations, the sympathetic nervous system contracts the arteries of the circulatory system resulting to the dilation of the pupils of the eyes. Also, during these situations, the blood sugar levels are raised since the hormones for stress kick in to combat the stress which in turn raises the blood sugar.
<span>By filtering the air so that the lungs so the lungs don't get infected</span>