What is visually different in the ecg reading from normal sinus rhythm?

The difference that can be found are:

Nodal rhythm: you can see the absence of the p wave (the first electric signal of an ECG)

Heart block: Heart block is a delay in the conduction of the electrical impulse through the atrioventricular node, the His bundle, or both branches, all located between the atria and the ventricles. There is a gap between the p and the rest of the ECG.

Atrial flutter: Designate atrial fibrillation whose amplitude, relative regularity and low frequency of the ripples are close to atrial flutter. Nevertheless, the f-waves are slightly irregular and rather positive in DII-III-VF shunts (unlike common atrial flutter). This aspect is in favor of a rather recent FA.

Atrial fibrillation: We observe:

*An absence of sinus wave P

*Auriculograms that vary anarchically in amplitude, shape, and frequency. They form a ripple of the baseline that may be relatively broad or barely visible (in aged forms), sometimes observed selectively in V1. These f waves can be confused with artifacts.

*Irregular RR intervals. 

Ventricular fibrillation: an Anarchic electrical activity of the ventricular myocardium. The resulting total desynchronization is responsible for circulatory arrest (asystole).

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .