用适当的数词填空。 ⑴There are ________ letters in English alphabet (字母表). ⑵There are ________ hours in a day. ⑶There are ________ days in a year. ⑷Monday is the ________ day of the week. ⑸There are ________ days in a week. ⑹There are ________ days in October. ⑺________ ________ is Christmas Day. ⑻There are ________ months in a year. ⑼Forty minus three is ________. ⑽There are ________ seasons in a year.