Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. Fill in the appropriate word in question 28

  University researchers have taken samples from a preserved dodo specimen in an (25) _____ to uncover the extinct bird’s family tree. They worked with the British Natural History Museum to collect and study genetic material from large number of specimens: a preserved dodo, the extinct solitaire bird, and 35 kind of living pigeons and doves. Their analysis (26) _____ the doo and the solitaire to be close relatives with the Nicobar pigeon, their nearest living relative. The dodo lived on Mauritius in the Indian Ocean. It was a flightless bird, bigger than a turkey. By 1681, all dodos had been (27) _____ by hungry sailors. The solitaire, which looked a bit like a dodo, had gone the same way by 1800. By extracting short pieces of the dodo’s DNA and (28) _____ these with the DNA of living birds, the scientists were able to deduce when the dodo evolved away from its relatives into a separate entity. The scientists can now (29) _____ assume that the dodo developed its distinctive appearance and features as a result of its geographical isolation. They are now convinced that it separated from the solitaire about 25 million years ago, long before Mauritius became an island.

A. researching

B. comparing

C. combining

D. studying