be used to 习惯于 get used to 习惯于 be useful to 对……有用 be well up in 精通,熟悉 be wild with joy 欣喜若狂 be willing to (do) 乐意…… be worried about 为……而担心 be worse off 处境较坏,情况恶化 be worth (doing) 值得(做) ...