Mark the letter A, B, C, or D on your answer sheet to indicate the correct one to complete each of the following sentences.
Trả lời câu hỏi dưới đây:
He has been waiting for this letter for days, and at ________ it has come.
A. at the moment -= ngay bây giờ
B. at last = cuối cùng
C. at present = hiện tại
D. at the end = cuối cùng