Linda often helps her mother ______ the housework on weekends.
—What’s ______ most useful invention in the 20th century? —______ computer, I think.
—The Mars-500 test will take about 520 days. —__________ I hope it goes well.
Tom _______ the USA. He _______ back in two months.A. has gone to; comes B. has gone to; will be C. has been to; comes D. has been to; will be
—I don’t know _______ now. —She is much better today.
_______ they are twin brothers, they don’t look like each other.