Antioxidants were first cast into doubt(a) ?????? (during/from/ since) a major
clinical trial in the U.S., in (b) ?????( which/ what / that) a very common
antioxidant, beta carotene, (c)?????? (was/ were/ is / are) tested for (d)
???????.. (its/ it?s / their/ theirs) efficiency against lung cancer in high ? risk
subjects (e) ????????.. ( To/ For/ With) the surprise and concern of the
scientists (f) ????????? (that/ those/ which/ whose) individuals taking the
supplement (g)???????. (intend/ intended) to reduce the risk of cancer were
(h)????????? (on/ at/ with) a significantly higher risk (i) ???????.. (for/
of/ to ) developing lung cancer.