Question 17: If you don’t know how to spell a word, you _______ look i

Question 17: If you don’t know how to spell a word, you _______ look it up in the dictionary.

• A. must
• B. will
• C. should
• D. ought

Cấu trúc câu điều kiện loại 1: If + S + V(s/es), S + will/can/shall/should/… + V(nguyên mẫu)