33£®He________computer  games  when  his parents  left  home£®So he didn’t know

    where  they were£®

    A.is playing   B. plays    C£®played   D£ºwas playing

35£®—Who is singing in the next room?Is it Betty?

    —It_________be her£®She has gone to London£®

    A.must    B£®mustn’t    C£®can    D£®can’t

36£®Tu Youyou is very popular because she is the only Chinese________won Nobel Prize

    in 2015£®

    A£®which    B£®whom    C£®who    D£®that