a.[B]

1. 较低的
   He belongs to the lower middle class.

   他来自中产阶级下层。

2. 低级的；下等的；下部的
   The lower berth is more convenient.

   下铺更为方便。

3. 下游的
   The lower valley of the river is often flooded.

   该河下游区域常遭洪水。

4. 南部的
   He lives in lower Manhattan.

   他住在曼哈顿南部。

vt.

1. 放下，降下；放低
   He lowered a bucket into the well to get some water.

   他将水桶放下井去取些水。

2. 减低；减弱
   We have to lower our expenses.

   我们得减少开支。

3. 贬低
   He would never lower himself by taking bribes.

   他决不会贬低自己的身份接受贿赂的。

vi.

1. 降落；降低；减弱
   Food prices lowered during the fall.

   秋天食品价格下降了。

vi.

1. （天空等）变得阴沉
2. 皱眉头，现出愁容[（+at/on/upon）]

adj.

1. less high in position, status, or amount.
   ▸ (often Lower) Geology  & Archaeology  denoting an older (and hence typically deeper) part of a stratigraphic or archaeological division:

   the Lower Cretaceous.
2. [in place names] situated to the south.

adv.

v.

1. cause to move downward.
2. make or become less in amount, extent, or value.
   ▸ (lower oneself) demean oneself.

v.

n.