Astudy was done to see whether a smaller dose of flu vaccine could be used successfully. in this study, the usual amount of vaccine was injected into half the patients, and the other half of the patients had only a small amount of vaccine injected. the response was measured by looking at the production of antibodies. in the end, the lower dose of vaccine was just as effective as a higher dose for those under 65 years old. what more do we need to know to be able to conclude that the lower dose of vaccine was equally effective at preventing the flu for those under 65?

the national environmental policy act (nepa) is a united states environmental law that promotes the enhancement of the environment and established the president's council on environmental quality (ceq). the law was enacted on january 1, 1970. to date, more than 100 nations around the world have enacted national environmental policies modeled after nepa.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.