Can viruses move by themselves? if not, how do they reach their host cell?

Match the deficiencies with their proper definitions: 1. deficiency disease 2. niacin (b3) deficiency 3.vitamin a deficiency 4.vitamin b1 deficiency 5.vitamin d deficiency 6.vitamin c deficiency a. abnormal conditions due to the absence of specific substances usually found in a normal diet b. susceptible to infection, partial or complete blindness, unhealthy skin c. fatigue, depression, irritability, low blood pressure, loss of appetite d. inflammation of the mouth, sores around the mouth, red and thickened skin, diarrhea, vomiting, etc e. weakness, bleeding into tissues, excessive bruising, softening of bones f. bones not normally hardened and become bent or twisted (answer format ex. 1 - a, 2 - b, 3 - c, etc.) will award brainliest

Which of these are associated with a positive mood ? select the two correct answers. dehydration healthful food choices lack of hunger good appetite

Natural selection causes organisms with mutations to become common