【推荐1】Some students ________ (register) for the calligraphy (书法) course last week. (所给词的适当形式填空)

【推荐1】The last day to cancel ________________ (register) and receive a full refund (退款) is June 15. (所给词的适当形式填空)

【推荐2】Readers should complete the _________ (register) before they can read the literary works on the website. (所给词的适当形式填空)

【推荐1】Once you have made an ________(appoint), you should keep it rather than break it.(所给词的适当形式填空)

【推荐2】Hold your horses. We still need some time to find a ________________(solve) to the difficult problem. （所给词的适当形式填空）

【推荐3】Central authorities should support Hainan’s daring reforms and ____(innovate), pushing for new achievements in the construction of the port. (所给词的适当形式填空)