Hemlock woolly adelgid is an insect pest to hemlock trees. it was introduced in the united states during the 1920's. it is not native to the united states and has few natural predators. to control this insect pest, scientists identified a species of predatory beetle, (pseudoscymnus tsugae). they hope to introduce this beetle to areas where the woolly adelgid is destructive, reduce the woolly adelgid population, and minimize the damage caused to hemlock trees. which of these questions best summarizes the research described? a) are hemlock trees important to the ecosystem? b) how does the woolly adelgid kill hemlock trees? c) can insect pests be used to control damaging predators in sensitive environments? d) can predatory beetles reduce environmental damage caused by the woolly adelgid?

Archeologists have discovered three sites showing conclusive evidence for the mastery of fire in tanzania, from a period slightly after the time that homo habilis was present in africa. these sites clearly were founded by homo erectus, the descendent species of homo habilis that migrated north, out of africa and into asia. homo erectus was known to have mastered fire, from ample evidence at sites in asia. there is no reason to attribute mastery of fire to homo ergaster, the descendent species of homo habilis that remained in africa.which of the following is an assumption on which the argument depends? (a) before their migration, homo erectus occupied african territory as far south as tanzania.(b) the strain of migration provided the selective pressure motivating homo erectus‘ mastery of fire.(c) homo ergaster would not have derived as much benefit from the mastery of fire as did homo erectus.(d) homo ergaster inherited all cultural knowledge from homo habilis, a species that did not have mastery of fire.(e) homo ergaster did not occupy regions as far south as tanzania until well after the time of these three sites.