balloons/bəˈluːn/名词气球People first flew in a balloon in 1783.人类于1783年首次乘热气球飞行。/bəˈluːn/动词(在大小、重量或重要性上)激增The silk of the parachute ballooned above me.降落伞的丝绸在我头顶上膨胀。想跟读,去练习