Answer:
veins because they carry low pressured blood due to which there is more chance for backward flow of blood and to prevent that they contain valves.
<em>hope</em><em> </em><em>it</em><em> </em><em>helped</em><em> </em><em>uh</em><em>.</em><em>.</em>
<span>
d jurassic period is the correct answer</span>
Egg cells, the ova are produced in the ovary
<span>The Earth rotates once in about 24 hours with respect to the sun and once every 23 hours,
56 minutes and 4 seconds with respect to the stars. Earth's
rotation is slowing slightly with time; thus, a day was shorter in the
past.</span>