阅读理解。
Science Daily (Apr. 27, 2008)-- Dutch ecologist Roxina Soler and her colleagues have
discovered that subterranean (地下的) and aboveground herbivorous (食草的) insects can
communicate with each other by using plants as telephones.Subterranean insects issue chemical
warning signals through the leaves of the plant. This way, aboveground insects are warned that the
plant is already 'occupied'.
Aboveground, leaf-eating insects prefer plants that have not yet been occupied by subterranean
root-eating insects. Subterranean insects send out chemical signals through the leaves of the plant,
which warn the aboveground insects about their presence. This messaging makes it possible for
spatially-separated insects to avoid each other, so that they do not compete for, the same plant.
In recent years it has been discovered that different types of aboveground insects develop slowly
if they feed on plants that also have subterranean insects and 'vice versa (反之亦然). It seems that a
mechanism (机制) has developed through natural selection,which helps the subterranean and
aboveground insects to communicate with each other. This avoids unnecessary competition.
Through the 'green telephone lines', subterranean insects can also communicate witha third party,
namely the natural enemy of caterpillars (毛虫). Parasitic wasps (寄生蜂) lay their eggs inside above
ground insects. The wasps also benefit from the signals sent by the leaves, as these help them find more
insects for their eggs.
The communication between subterranean and above- ground insects has only been studied in a
few systems. It is still not clear how widespread this phenomenon is, say the researchers.
1. How do subterranean and aboveground insects communicate with each other?
A. By sending signals through the leaves.
B. By giving off particular smells.
C. By soft and beautiful sounds.
D. By the signals sent by parasitic wasps.
2. After finding a plant occupied by root-eating insects, aboveground insects will usually ________.
A. send out warning signals
B. choose to leave the plant
C. compete for the same plant
D. fight with the root-eating insects
3. Aboveground insects will develop more quickly if their food plants ________.
A. are often visited by parasitic wasps
B. are not occupied by mot-eating insects
C. have more green leaves
D. have more subterranean insects
4. What does the underlined part 'a third party' in Paragraph 4 include?

A. Aboveground insects.
B. Root-eating insects.
C. Caterpillars.
D. Parasitic wasps.

5. What would be the best title for the passage?
A. Communication between different insects
B. How do animals avoid competition?
C. Insects use plants as telephones
D. When plants have subterranean residents