1.You won't know if it fits you until you it on.
A.will try B.are trying C. are to try D.have tried
2.The conference a full week by the time it ends.
A. must have lasted B.will have lasted C.would last D. has lasted
3. It seems oil from this piece some time. We’ll have to take the machine apart to put it right.
A. had leaked B. is leaking C.leaked D.has been leaking
4. Great as Newton was, many of his ideas today and are being modified by the work of scientists of science of our time.
A. are to challenge B. may be challenged C. have been challenged D. are challenging
5. John told Mary that he what he was doing during the holidays.
A.had just been asked B. has just asked C.was just asked D. just asked