人行道上挤满了穿着正装的人。

The ___sidewalks are filled with people in business attire.

清晨人们喜欢在人行道上散步。

People enjoy walking on the ___sidewalks in the early morning.

孩子们在人行道上玩耍很安全。

It's safe for kids to play on the ___sidewalks.