Before experimental drugs can be brought to market, they must undergo many rigorous trials to ensure they deliver their medical benefits effectively and safely. one method commonly used in this process is to compare the effect of a drug with that of a placebo in double-blind tests. which of the following correctly describes a double-blind test?
a. the researchers apply two-layered blindfolds to the study participants so that they cannot see whether they are receiving the drug or a placebo.
b. neither the researchers nor the study participants know who is receiving the drug and who is receiving the placebo.
c. the researchers know who is receiving the drug and who is receiving the placebo, but they do not know what the supposed effects of the drug should be.
d. the researchers do not know who receives the drug or the placebo, but the participants know and tell them later.
e. none of the above is correct.

Where does all the water go? according to the environmental protection agency (epa), in a typical wetland environment, 39% of the water is outflow; 46% is seepage; 7% evaporates; and 8% remains as water volume in the ecosystem (reference: united states environmental protection agency case studies report 832-r-93-005). chloride compounds as residuals from residential areas are a problem for wetlands. suppose that in a particular wetland environment the following concentrations (mg/l) of chloride compounds were found: outflow, 60.4; seepage, 73.7; remaining due to evaporation, 26.4; in the water volume, 46.8. (a) compute the weighted average of chlorine compound concentration (mg/l) for this ecological system. (round your answer to one decimal place.) mg/l (b) suppose the epa has established an average chlorine compound concentration target of no more than 58 mg/l. does this wetlands system meet the target standard for chlorine compound concentration? yes. the average chlorine compound concentration (mg/l) is too high. yes. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is too high.

According to cell theory; which structures carry out the basic function of living things? a. atoms b. organs c. cells b. nuclei

Prokaryotic and eukaryotic cells are different in many ways other than the presence or absence of a nucleus. if both archaebacteria and eubacteria are prokaryotic cells, then why are archaebacteria more closely related to eukaryotic cells than they are to eubacteria?