False because mainstream smoke is defined as smoke from a cigarette or pipe. Second hand smoke is smoke that has been inhaled by someone then exhaled, making you the "second" one to breath it :)
Get in a comfortable spot and then try to sleep early then u do
The benefit of the circuit of fetal blood course through the ductus arteriosus is the ductus arteriosus will permit more blood to go to the placenta and sidestep the lungs (since there is no blood required there yet). I hope the answer will help you.
It's important to only trust health information that is backed up by scientific proof because people can put things out there that might not be true, or even worse, make your health worse, whether that health is physical, mental, or emotional.