Human embryos with the wrong number of chromosomes are surprisingly common, both among IVF patients and natural births.

Do you mean "natural pregnancy?"  Aneuploidy generally results in miscarriage, which we don't call a "natural birth."

marijuana-related emergency room visits

How does marijuana relate to an emergency room visit?  I can't find any suggestions anywhere that any plausible dose of marijuana causes any physiological response that might qualify as a health emergency.

when the Dutch pseudo-legalized marijuana, use of harder drugs stayed stable or went down, but all their study actually shows is that the ratio of marijuana users : hard drug users went down.

Typo?  If "hard drug users" is in the denominator and goes down relative to the numerator, then the ratio increases – i.e., goes up.

thousand

Typo: should be "thousands"

game off spy vs spy

Typo: off >> of