他们在市中心租了一套两居室的公寓。

They rented a two-bedroom ___flat in the city center.

我买了一双新的平底鞋，走路很舒服。

I bought new ___flats that are very comfortable for walking.

孩子们在操场的大场地上踢足球。

The children play soccer on the large ___field of the playground.

这首曲子中有一个降E音。

There's an E ___flat in this piece of music.