9. Why, even thoough they
have an open circulatory
system, can flying insect slike
flies beat their wings with
great speed?

Gap-fill exercise

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In insects the system is open
this system does participate in
the exchange process and oxygen
supply to tissues. Gases go and
out through independent tracheal
system allows direct contact cells
with the air. Therefore an
can supply the oxygen
demand of fast-beating wing muscles
having open circulatory .