2.000-1735=265, aka his discretionary allowance
Answer: The only way to have intercourse safely is to use protection, and even sometimes its not ultimately guaranteed the woman won't become pregnant. If you don't use protection, the woman is most likely going to get pregnant, so either use protection or just don't have intercourse at all. Also make sure you are mature and old enough to have intercourse in the first place.
Answer: Refractory period of the cardiac action potential
Explanation:
Unlike the skeletal muscle which can be reactivated before it reaches a contraction, cardiac muscle must wait before it is almost completely relaxed to be activated again (because of its long refractory period), so one cannot make an increase in strength of contraction with a high frequency of stimulations.
<span>Heart Rate Reserve, HRR. Heart rate reserve (HRR) is the difference between resting heart rate (HR<span>rest) and maximum heart rate</span> (HRmax). Heart rate reserve is used when determining exercise heart rates. The Karvonen formula is used to calculate exercise heart rate at a given percentage training intensity.</span>
