成语“无人问津”出自《桃花源记》，文中对应的原句是：____，____。____。____，____，____ ，____。
点M（﹣1，5）向下平移4个单位得N点坐标是____．
—Do you want to keep goldfish?
—No, they are ______ difficult for me______ take care of.
