EXERCISE 2. HÃY CHO BIẾT TỪ ĐỒNG NGHĨA HOẶC GẦN NGHĨA, TỪ TRÁI NGHĨA C...

6. It wasn’t obligatory to submit my assignment today.A. My assignment must have been submitted today.B. I needn’t have submitted my assignment today.C. My assignment was required to submit by today.D. I mustn’t submit my assignment today.