张择端的《清明上河图》形象展现了哪个城市风貌，是当时城市生活的百科全书式的艺术长卷（ ）
A：长安
B：洛阳
C：临安
D：汴京
—I've decided to quit this job，but I'm afraid I won't be able to find a better one.
—________.You never know until you try.
①有明确的奋斗目标 ②对自己要求比较严格
③能抵御来自外界的干扰 ④容易受各种不良因素的干扰
It's impolite ____information directly when asking for help.
