慢速英语:Scientists Use Sound Waves to Find Hidden Cracks in Bridges, Airplanes
日期:2015-04-13
短语讲解：
1. Thirteen people died and more than 140 others were injured.
more than 多于
例句：There is more than a whiff of propaganda.
所含之宣传实在不止一点点。
2. Mr. Croxford says his ‘phased array' system of sending out sound waves returns harmonics -- echoes of different frequencies.
send out 发送; 发出
例句：I forget to send out your having believed.
我忘记发你的信了。
3. "By using this novel approach we can now pick up a crack close to a hole, which is directly relevant, to say, aerospace applications, where they're worried about cracks growing from rivet holes, things like that."
pick up 捡起; 接载
例句：I pick up my sister from her school.
我到学校接妹妹。
worry about 担忧
例句：Don't worry about being late. It's fine.
别为迟到担心了 没有关系。