The old couple has ____ a lot since their only son was killed in an accident two years ago.
Look out! Don’t get too close to the house ______ roof is under repair.
The teacher said that Columbus _______America in 1492.
—When Tom________,please let me know.—Mary said when Tom________,just tell her about it.
—If you like the model car, you can _____ it. I don’t want it.—Thank you very much.
My friend Jennifer, ____ help I’ve made great progress in my studies, will leave for Canada next week.