根据句意，用括号内所给单词的适当形式填空。
小题1:His father looked______ (angry)at his son. Because he often makes mistakes.
小题2:Next Sunday will be my brother’s __________ ( nine ) birthday.
小题3:The children are very happy. They can’t hide their_________(excite)
小题4:_______ (luck), he found his lost pen just now.
小题5:The swallow flies to_________ (north) countries in summer every year.
小题6:Some people think learning English is________ (use).That’s wrong.
小题1:angrily
小题2:ninth
小题3:excitement
小题4:Luckily
小题5:northern
小题6:useless
小题1:考查副词的用法。修饰look at短语，应该用副词。angry的副词形式是angrily。故填angrily。
小题2:考查序数词。“九岁生日”是ninth birthday。故填ninth。
小题3:考查物主代词的用法。形容词性物主代词their后跟名词。故填excitement。
小题4:考查副词。修饰整个句子，用副词。lucky的副词形式是luckily。故填Luckily。
小题5:考查词性转换。north“北方”；northern“北方的”，后加名词。故填northern。
小题6:考查形容词作表语。根据句意可知，应该用useless“无用的”。故填useless。