—______
A:It's wonderful.
B:It's my pleasure.
C:It's very nice of you.
①若sinAsinB=2sin2C,则0<C< π4 ;
②若a+b>2c,则0<C< π3 ;
③若a4+b4=c4.则△ABC为锐角三角形;
④若(a+b)c<2ab,则C> π2 •
结合语境修改画线语句,最恰当的是( )一到深秋,小院内全靠这一棵柿子树独撑天下。那时树叶即将落尽,满树的柿子都已火红。那一树柿子张灯结彩,①使小院点缀得红红火火、热热闹闹。这树柿子品种极好,色丽如焰,皮薄如纸,②甜瓤如蜜。