Listen,you can hear the workers are b______a subway in the city填什么单词

Listen,you can hear the workers are b______a subway in the city填什么单词

building
不明白的再问哟!请记得采纳,多谢!

building
在建造一条....

Listen,you can hear the workers are building a subway in the city

building
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building 修建 be动词+动词ing
留心听，你能听见工人们正在修地铁在这个城市