Two scientists are observing a group of children eating at snack time. After watching the children, Scientist A says the children eat because they are hungry. Scientist B says the children eat because their friends are eating. Which scientist's conclusion is valid? A. Scientist B's conclusion is valid because it is supported by evidence. B. Neither conclusion is valid. Conclusions cannot be drawn from observations. C. Scientist A's conclusion is valid because eating is necessary to stay healthy. D. Both scientists' conclusions could be valid.

Aresearcher designed an investigation to test what effect eating different types of food would have on blood insulin levels. she selected 10 male subjects who were all 25 years of age and in good health. the experiment took place over 3 days. at 8: 00 a.m. on each day, the subjects ate a meal consisting of only 1 type of food. they had their blood insulin levels measured after consuming the meal. on day 1 they ate a high fat diet, on day 2 they ate a high protein diet, and on day 3 they ate a high sugar diel what is the independent variable in this experiment? a the age of the subjects b the blood insulin level c the type of food consumed d the time of day the meal was consumed

Find the mass of the cone using the triple beam balance. a. 543.0 g b. 542.0 g c. 504.28 g d. 502.8 g select the best answer from the choices provided a b c d

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