Answer:
12
Explanation:
Suppose the four different strains are P, Q, R, S. Thus, the first infection can be from any of the four strains and it occurs in 4 ways.
Since an individual cannot be infected again with the strain from which he/she is been previously infected;
Then, at the second time;
The possible number of strain to be infected with = 4-1 = 3 ways
Thus; the number of possible different levels of severity can be viewed by forming two lettered word P, Q, R, and S without repetition which is:
= 4 × 3
= 12
Answer: c. Flower
Explanation:
An angiosperm can be define as a group of vascular plants. These plants are flower bearing which means they conduct sexual mode of reproduction through flowers. The flower exhibit male and female reproductive structures the fertilization of which produce seeds and fruits.
Number 3 is the plants take in carbon dioxide and release oxygen so that we can breathe and the use the carbon
any time of the day the moon will appear