We ought to clean our teeth ________ A. after breakfast B. before breakfast C. before bedtime
We ought to clean our teeth ________
A. after breakfast
B. before breakfast
C. before bedtime
D. both B &C
Chọn D
Dẫn chứng “Secondly, we should brush our teeth with a toothbrush and fluoride toothpaste at least twice a day-once after the breakfast and once before we go to bed”