trade back up贸易回升
Trade opening up贸易开放
trade-up升级
Trade Up with Installments分期付款以旧换新;分期付款
To trade up以廉价物品交换高级物品
Trade Up A Bit贸易一点
Our country foreign trade speed-up我国外贸增速
up trade针织裁剪行业
PHRASAL VERB（动词词组） If someone trades up, they sell something such as their car or their house and buy a more expensive one. 卖掉 (汽车、房子等) 去买更贵的东西
Gas prices are discouraging small car owners from trading up to SUV's.
汽油的价格使得小车车主不敢卖掉小车购买运动型多用途汽车。