Read the short news and decide which prepositions complete the gaps. Mattress covers do not help dust mite allergies, study says Based (1) ______...

Read the short news and decide which prepositions complete the gaps. Mattress covers do not help dust mite allergies, study says Based (1) ___________ two dozen clinical trials, U.S. researchers find that expensive mattress covers make no difference in reducing dust mite allergies or their symptoms. (2) __________ to 40 percent (3) ________ the world population has allergies, and dust mites are thought to be one of the most common causes. Doctors often tell patients to buy special mattress and pillow covers despite a lack of evidence they relieve the problem, the authors say. "Based on this analysis which combines data (4) __________ many different studies, there doesn't seem to be any benefit to using dust mite covers to prevent allergic disease or to prevent symptoms," lead author Whitney Arroyave told Reuters Health. a. (1) up; (2) up; (3) from; (4) of b. (1) in; (2) at; (3) of; (4) with c. (1) behind; (2) after; (3) of; (4) from d. (1) on; (2) up; (3) of; (4) from e. (1) with; (2) up; (3) of; (4) of