Scientists are conducting a study on the effectiveness of a new drug on memory loss. they are giving some of the test subjects the new drug to find out if it improves their long-term memory. which are possible limitations of this study? check all that apply.
test subjects may want to participate in additional experiments.
test subjects may think they should be paid more.
test subjects may get bored and want to quit early.
test subjects may have to travel during the experiment.
test subjects may have full-time jobs.

Due to its nature, this study will require observations of the patients over a long period of time.

Thus, the possible limitations of this study are:

Test subjects may have to travel during the experiment.  

Test subjects may have full-time jobs.

Furthermore, as the subjects have memory problems, if the data is gathered by themselves, it may not be accurate. If the data is gathered by the scientists, then the patients may have difficulties in coming in, especially if they have full-time jobs or need to travel.

last two D, E.

explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.