请在需要的地方填入恰当的不定冠词,不需要的画"/".
1 I have ______ idea.It is ________ good idea.
2 There is ________"s" and ______"u" in the word "us".
3 This is _____new watch.It is______expensive watch.
4 Mr Green is _____English teacher.Now he works in______middle school in _______China.
5 What ______nice day! Let's play ______football.
6 It takes Daniel __________hour to make _____model plane.
7 ______elephant is ______animal .It is _______large animal.
8 She wears her hair in ______1990s style.
_______(a/an)用在元音开头的可数名词前.
