In our class, ________ of the students ________ girls.
A.three fifth, is B.third fifth, are C.three fifths, are
________ you are interested in playing computer games, you’ll have trouble giving it up.
A.Once B.Since C.Though
— What do you think of the program?
— Great! It has made important contributions to ________ our school clean and tidy.
A.keep B.have kept C.keeping
His grandma saw the changes ________.
A.himself B.herself C.hers
________ he is busy, ________ he is glad to take part in volunteer activities.
A.Though; but B.Though; however C./; but
So far, the population ________ about two percent.
A.has increased by B.has increased to C.increased by
