题干
Don't worry about your English. Work hard and you'll improve it ____.
A：hand by hand
B：arm in arm
C：one by one
D：step by step
答案(点此获取答案解析）
D
Don't worry about your English. Work hard and you'll improve it ____.
A：hand by hand
B：arm in arm
C：one by one
D：step by step
