看图，选择相应的介词填在题前括号里。

1. There are many flowers _____________ the river. [ ]

A. in

B. near

C. on

2. The ducks are _____________ the water. [ ]

A. in

B. on

C. under

3. The bridge is _____________ the river. [ ]

A. behind

B. on

C. over

4. The girl is _____________ the tree. [ ]

A. on

B. under

C. near

5. The houses are _____________ the trees. [ ]

A. behind

B. in front of

C. over

心脏有一结构叫卵圆窝，在什么解剖结构上（）.

A.在左房的左心耳上

B.在房间隔上

C.在肺动脉上

D.在主动脉上

E.在室间隔上