There have been a number of ______ between police in riot gear and demonstrators.

【正确答案】 C

【答案解析】 句意：防暴警察和示威人群已发生多次冲突。clasp钩，扣子。clamp钳；夹钳。clash冲突。clip夹子，回形针。结合句意，只有C选项合适。