A．Plants can produce some poisonous chemical for defence against insects.
B．Insects have been eating plants for many million years.
C．Insects have developed ways of dealing with poisonous chemicals produced by plants themselves.
D．Insects have already developed some resistance to man-made poisons.

A．On the cliffs of an island.
B．In the eaves of an island.
C．Under the holy picture of the Virgin.
D．In the Virgin convent of an island.