Tom ________ with his aunt and uncle because his parents have gone abroad for a holiday.
2004年一则报道说，杭州新近开张一家大型娱乐场所，“总统包厢”每个6800元，服务员一律采取跪式服务，如此奢侈的消费竟然生意奇好，门庭若市。这种消费方式是（ ）
一个正方形的面积是15，估计它的边长大小在( )
