重写句子：Alanpassedthetest.Alanhadstudiedhard.Alanhadunderstoodthematerial.(complexsentence)
Ifyou’resittingaroundalonelycampfireatnight,thehowlofawolfcansoundpretty______.
Notallbirdscanfly,______doallbirdsbuildnests.
Ittookmeamonthtogetrid_______thecough.
Theboycomplained_______apaininhisstomach.
