it is safe to --- that the price of cars will go down

C。ensureto ensure that 为使；为确保；确保这一点assume [ə'sju:m; ə'su:m]vt。呈现,呈(某种形式、面貌等)；具有(…的作用、特征、性质等)；采取：；采用(某种方式等)：vi。僭越；装腔作势invest [in'vest] vt。投资；覆盖；耗费；授予；包围vi。投资,入股；花钱买ensure [in'ʃuə] vt。保证,确保；使安全persist [pə'sist,-'zist] vi。存留,坚持；持续,固执vt。坚持说,反复说