请高手帮我听四个英文句子中的单词

请高手帮我听四个英文句子中的单词
四句英文句子,我自己听出来了绝大部分,请高手帮忙
我听出来的：
1. over the next week, the stem cells from David's blood will be cultivated to grow and
multipy into a concertrated ? of millions of stem cells.
2.David's heart was destroyed by a ? that attacked his heart muscle, causing a condition
known as cardiomyopathy.
3.This is an area where ? considerable damage to people, and we are exploiting a biology
which we haven't fully understand. and i think under those circumstances we have to do it in
a very careful way.
4. Adult stem cells have even been targeted as a cure for baldness, to rejuvenate ?
问号表示我不知道的
四句的音频：
http://fzhang.cn.googlepages.com/1.mp3
http://fzhang.cn.googlepages.com/2.mp3
http://fzhang.cn.googlepages.com/3.mp3
http://fzhang.cn.googlepages.com/4.mp3