BBC在线收听下载:平壤举行游行庆祝朝鲜劳动党七大闭幕

短语讲解：

1. But he has so far offered few policy details, although the spokesman for him has already pledged a radical overhaul of the political system.

so far 迄今为止; 到目前为止
例句：It is merely a hypothesis; so far.
到目前为止，这仅仅是一种假设。

2. A new report on the status of the world plants says that more than 2000 new species were discovered last year alone, including orchid, three meters tall.

more than 超过; 不只是; 很; 在…次以上
例句：Margaret needed support more than ever.
玛格丽特比以往更需要关心。

3. Several large tornados have struck the US state of Oklahoma, killing at least two people.

at least 至少
例句：In fact it requires at least n generators.
事实上，它至少要有n个元素。