用所给单词的正确形式填空

61.Sharing a problem is like ____________（cut）it in half.

62．Meimei celebrated her ____________(ten) birthday at home last Monday.

63．I was doing the dishes when my mobile phone ____________（sudden）rang.

64．Nowadays it is ____________（help）for everyone to learn how to use computers.

65．Many ____________（tour）around the country come to Changbai Mountain every year.