当我答应帮他的忙时,他立刻高兴起来.{cheer up}中国正在大力发展以赶上世界上一些发达国家.{catch up with}
热心网友
1、When I agreed to help him, he started to cheer up immediately.2、China is developing itself rapidly so as to catch up with some advanced countries in the world.
热心网友
第一句话用When I agreed to help him, he sheered up immediately更加简捷明了.