There are over 2,000 varieties of snakes, ________are harmless to humans. A. mostly they B. most of them C. most of which D. which mostĐoạn văn8/87SECTION II: LEXICO – GRAMMAR Part 1: Questions from 16 to 36. Choose the best answer to each question. There are over 2,000 varieties of snakes, ________are harmless to humans. mostly theymost of themmost of whichwhich mostGiải thíchChọn C