BBC在线收听下载:奥巴马就波士顿爆炸案发表讲话 要将凶手绳之以法

短语讲解：

1. A search and rescue effort is continuing in the American state of Texas after a huge explosion at a fertilizer plant on Wednesday night, killed up to 15 people and injured hundreds.

up to 直到；做…；在于…；能胜任
例句：In 2013 growth may nudge up to 5.7%.
在2013年，可能会推动经济增长高达5.7%。

2. And also spoken to local officials to make sure they have all the support and assistance that they need from the state.

make sure 把事情弄清楚，核实或查明某事物
例句：How do you make sure this is clear?
你怎么能确定这足够明确呢？

3. At least two children are among the dead. Dozens of people have been wounded.

at least 至少
例句：Go home and rest for at least one week.
回家最少休息一个星期。

4. The regional group, UNASUR, is expected to give its backing to results which awarded a narrow victory to make Nicolas Maduro the chosen successor of the late president Hugo Chavez.

be expected to 被期待做某事；有望做某事；期许
例句：That could hardly be expected to last.
这很难预计将持续多久。