用括号内所给单词的适当形式填空。
1.It’s ________ (believable)that the little girl won the singing competition.
2.Are you completely_______ (truth)with me?
3.Who is the_______ (own)of the schoolbag?
4.Alice gave up the English exam because of her ________ (ill).
5.He volunteers his weekend ______ (help)people in need.