I'm like so sorry that I'm a teacher on this website but please stop cheating.
Radiation is the transfer of energy through electromagnetic waves. for example, infrared radiation travels towards you, and gives its energy to the molecules in your body, warming you up.
This is a chronological sequence. Chronological usually lists a series of events in order, starting from the earliest to the most recent.
The main idea is the first sentence (1). The rest of the sentences support the main idea that cockroaches have some amazing characteristics.
