题干
Roads in the ____ (mountain) area have been badly damaged by the earthquake.
答案(点此获取答案解析）
mountainous
Roads in the ____ (mountain) area have been badly damaged by the earthquake.
的图象与
的图象的两相邻交点间的距离为π，要得到y=
的图象，只需把y＝sin
x的图象( )