Below each of the following incomplete sentences are two expressions.
complete each sentence by choosing the expression that is parallel in form with an expression
that is already a part of the sentence.

moderate control of tsetse flies can be achieved by sterilizing them with radiation or
a. by spraying them with insecticide
b. spray them with insecticidal sprays
tsetse flies feed by piercing the skin with their mouthparts and .to suck the blood of animals and humansb. sucking the blood of animals and humans

Ascientist is investigating the effects of salinity on fish development. he places fertilized fish eggs in an aquarium that contains low salinity and observes their development. what factor would improve experimental design the most? place the fish eggs in the open ocean because that is the natural habitat include another aquarium that has normal salinity to compare to the low salinity aquarium include an aquarium that replaces salt with sugar to confirm that the effects are specific to salt grow algae with the fish eggs in order to provide adequate nutrients to the developing embryos