Here's a short story:

Insects (from Latin insectum, a calque of Greek ἔντομον [éntomon], "cut into sections") are a class of invertebrates within the arthropod phylum that have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. They are the most diverse group of animals on the planet, including more than a million described species and representing more than half of all known living organisms. The number of extant species is estimated at between six and ten million, and potentially represent over 90% of the differing animal life forms on Earth. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, a habitat dominated by another arthropod group, crustaceans. 

The life cycles of insects vary but most hatch from eggs. Insect growth is constrained by the inelastic exoskeleton and development involves a series of molts. The immature stages can differ from the adults in structure, habit and habitat, and can include a passive pupal stage in those groups that undergo 4-stage metamorphosis (see holometabolism). Insects that undergo 3-stage metamorphosis lack a pupal stage and adults develop through a series of nymphal stages. The higher level relationship of the Hexapoda is unclear. Fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonflies with wingspans of 55 to 70 cm (22–28 in). The most diverse insect groups appear to have coevolved with flowering plants. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: What is the life cycle of insects?
Guess: It varies but most hatch from eggs

Question: How is it's growth constrained?
Guess: by the inelastic exoskeleton

Question: How else?
Guess: development involves a series of molts

Question: How many stages of metamorphosis are there?
Guess: Four

Question: What are insects?
Guess: a class of invertebrates

Question: How many body parts do they have?
Guess: Three

Question: What are they?
Guess: head, thorax and abdomen

Question: Are they diverse?
Guess: Yes

Question: How many species?
Guess: more than a million

Question: How many extant species are there?
Guess: estimated at between six and ten million

Question: What does that represent?
Guess: represent over 90% of the differing animal life forms on Earth.

Question: What kind of environment can they be found?
Guess: nearly all

Question: Even in oceans?
Guess: Yes

Question: What have they found in the Paleozoic Era?
Guess: Fossilized insects of enormous size

Question: What kind was found in this era?
Guess: giant dragonflies

Question: How big?
Guess: with wingspans of 55 to 70 cm

Question: Have they coevolved with anything?
Guess: Yes

Question: What?
Guess: flowering plants.

Now answer the following question in the same format.

Question: What is the metamorphosis stage of an adult?

series of nymphal stages