In the USA people ___ bikes must wear helmets.A. on B. go C. at
改错。(把错误的选项写在括号内,并在横线上改正。)(6分)
Tom ________ his homework on Sundays.A.doesn't do B.doesn't C.isn't do
________ mother is a doctor.A.She B.He C.Her
My uncle is a teacher.He ________ me Chinese.A.teaches B.teach C.teaching
She is ________.A.a engineer B.engineer C.an engineer