prevents backflow into the left atrium
Answer:
b) there are 56 deer in 1000 acres of area.
Explanation:
If a person has 1000 aces of land and a local wildlife biologist tell him that on every 18 acres only one deer is present so in 1000 acres there are 56 deer are present.
calculation;
1 deer ------ 18 acres
x --------- 1000 acres
by cross multiplication, we get
18 x = 1000
both side divided by 18, we get
x = 55.5
by rounding off we get
x = 56
Some man-made fibres, too, are derived from naturally occurring polymers. For instance, rayon and acetate, two of the first man-made fibres ever to be produced, are made of the same cellulose polymers that make up cotton, hemp, flax, and the structural fibres of wood.