1、drop out

退學;退出(比賽等)

He'd dropped out of high school at the age of 16.

他 16 歲的時候就從中學退學了。

She dropped out after 20 kilometres with stomach trouble.

20 公里后她因胃痛而退出了比賽。

拒絕接受傳統規范;離經叛道;擯棄社會習俗

She encourages people to keep their jobs rather than dropping out to live in a commune.

她鼓勵人們堅持工作而不是離經叛道地去過公社生活。

2、concrete

混凝土

The posts have to be set in concrete.

這些柱子必須用混凝土固定。

They had lain on sleeping bags on the concrete floor.

他們就躺在鋪在混凝土地面上的睡袋上。

具體的;確實的

He had no concrete evidence.

他沒有確鑿的證據。

There were no concrete proposals on the table.

沒有具體的提議可供討論。

(計劃或觀點)固定的，不變的

As Mr Blunkett emphasised, nothing is yet set in concrete.

正如布倫基特先生所強調的，一切都還沒有定下來。