<span>This is a sign of the primary stage of syphilis. These lesions, or chancres, will show up in the exact spot that the bacteria originally entered the body. This is generally a sign of the infection. The illness often incubates for long periods of time, from between ten and ninety days, so it could be months from the original contact.</span>
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.
Those are really wacky answers to choose from. It isn't B.They are usually man made. It's not C. we still need to be careful. It is not D. It is always your responsibility for whatever you do. It shouldn't be A, but that would kind of make sense. I would choose A.
Answer:
tapeworms and lice are examples of parasites that can cause diseases in humans
Explanation: