1.delivery service 送货服务

例句：Alibaba is experimenting with a drone delivery service as the Chinese ecommerce group seeks ever faster ways to put its goods in eager consumers'hands.
阿里巴巴（Alibaba）正在测试无人机送货服务，这家中国电子商务集团寻求以更加快速的方式，将商品送到急切的消费者手中E@gKJ_M|tY7P#。

2.on-demand 按需

例句：Both engines have on-demand engine coolant pumps to improve fuel economy and increase power.
这两个引擎都按需发动机冷却泵，以改善燃油经济性和提高功率.%(vW1@mv([l%RZZ~z。

3.be great for 对..很好

例句：It was great for me, too.
这对我来说，也是很好的0MC4^l9a-V&XK@R。

4.limited time 有限的时间

例句：How will you use the limited time you have?
你将如何使用你所拥有的有限的时间？