the experiments must be repeated several times to be sure the results are the same;
(the experiments; must be repeated; T:several times; to be sure the results are the same) (the experiments; to be; sure the results are the same) (the results; are; the same)
the experiments the experiments the results
must be repeated to be are
T:several times to be sure the results are the same
sure the results are the same
the same