2021-054

About random networks and scale-free networks, check the incorrect answer.

1. Many networks of scientific and practical interest, from the WWW to the subcellular networks, are scale-free;
2. In a random network most nodes have comparable degrees and hence hubs are highly unlikely. Hubs are not only tolerated, but are expected in scale-free networks;
3. The main difference between a random and a scale-free network comes in the tail of the degree distribution, representing the high-\(k\) region of \( p_k \);
4. In a network with a power-law degree distribution, most nodes have only a few links. These numerous small nodes are held together by a few highly connected hubs;
5. None of the above is incorrect.

Original idea by  Adson N Alves