21. They could not go to the theater together because his free time never ______ with hers.
    A. collide   B. comply   C. coincide   D. cope

collide  碰撞，相冲撞
collision  冲突
bump  撞击 
bump into  邂逅，偶然遇到

comply (with)  遵守（法律法规）
adhere (to)  坚持，遵守，粘着
conform (to)  符合，遵守（法律法规）

cope (with)  处理