Chọn đáp án đúng nhất A, B, C hoặc D để hoàn thành các câu sau 1. Nam didn't know__________to find more information about the course. A. when B. how C. Where D. All are correct 2. He asked_______it was too early to apply for the course. A. if B . that C. why D. A & C are correct 3. Minh is_______ the most successful student in my class. A. so long B. by how C. by far D. so now 4. My grandfather is the ................ oldest artisan in the village; Ngoc's grandfather is the oldest. A. first B. second C. most D. one 5. Lan couldn't decide_________ to work with on the project. A who B. what C. how