我国环保部门统计,在我国七大水系中,不适合作饮用水源的河段已接近40%,城市水域中78%的河段不适合作饮用水源,约64%的城市地下水受到污染,全国农村有3亿多人饮水不安全。这告诉我们( ) ①我国水资源紧缺 ②我国水资源面临严峻形势 ③水是生命之源 ④水资源短缺严重影响人们的生活质量和社会发展 A.①②③ B.①②④ C.①③④ D.②③④The positive meanings_____ words in an ad and how they are presented in an interesting way play an important role in promoting a product. A. are attached to B. attached to C. attaching to D. having attached to