When did Li Mei begin to learn English— At the age of six, she began teaching English.

Remember not to pretend to know what youdon’t know.— _____. My last lesson is still fresh.

Mark lives in a big pleasant room ________ approximately 5 meters by 6 meters.

When I am walking in the street,I________some ads every time. —So am I.I hate it.It’s a waste of paper.

nobody gave him any help, he ________ have done the research on his own.