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
For number 8:
all radio waves,
infrared radiation,
visible light,
ultraviolet radiation,
X-rays,
gamma rays.
Dry and arid parts of the world with little to no rain.
Answer:
A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm. Within the cytoplasm lie intricate arrangements of fine fibers and hundreds or even thousands of miniscule but distinct structures called organelles.
Explanation:
Answer: heavy eroded particles settle out of moving water
Placer deposits forms when rocks weathered due to the effect of water. The heavy minerals from the rocks get settled down in water. Minerals that form placer deposits have high specific gravity, they are resistant to chemical weathering process and are durable.
