01 现在进行时 （be+ -ing）

动作描写

They are walking in the park.

They are working on the roof.

The man is watering a tree.

状态描写

The man is wearing a work vest.

They are waiting in line.

02 一般现在时，一般现在时被动语态（be+p.p.）

描写“事物或背景的状态”

Various kinds of dessert are on display.

Most of the seats are taken.

The flowers are planted in a row.

03 完成时（have+p.p.） or （have + been + p.p.）

描写事物状态，强调某一时间点结束的事情对现在的影响。

The cars have stopped at the traffic light.

The table has been set for a meal.

Some fruits have been arranged.

Files have been placed on the desk.

04 There be 句型（There is / are ……）

描述“有……”，须仔细听清be 后面的名词或名词后连接的动词或状态短语。

 There is a tree between two benches.

 There are vehicles on the bridge.

 There are cars parked on both sides of the street.

05 进行时被动语态（be+being +p.p.）

经常被使用在选项里，以起到与“描述事物状态”的句子混淆的作用，不常作为正常答案出现。所以在听到being 这个词后，要关注是否有动作的主体-人。

The magazines are displayed on the rack.

The magazines are being displayed on the rack.

The boxes have been stacked up on the floor.

The boxes are being stacked up on the floor.