The process of fertilization involves the deposition of sperms into the vagina to the egg cell during sexual intercourse. Sperms make their way towards the cervix and uterus, and eventually goes to the fallopian tubes. <span>Only a few hundred will remain as they interact with the egg through the use of their heads and movement patterns.
</span><span>The process of implantation happens when the embryo, the fertimized eggs develops inside the fallopian tube after three days, and then travels to the uterus.</span>
Answer:
Oil
Explanation:
Since, unlike oil, source like wind, solar, water etc. come naturally we don't and can't replace them but when the viscosity in oil has been used up it must be change to allow the proper functioning of the machine.
