VOA慢速英语:Groups Seek $4 Billion for Child Vaccines

a lot和a lot of区别

a lot可用作名词性词组。 如：
I can learn a lot about Chinese history. 我可以学到很多有关中国历史方面的知识。
a lot也可作副词词组，修饰动词，意思是“十分”、“非常”，相当于very much. 如：
I like Chinese action movies a lot. 我非常喜欢中国的动作片。
a lot of是起形容词作用的词组，后接可数或不可数名词，相当于many或much. 如：
There are a lot of / lots of famous movie stars in the USA. 美国有许多著名的电影明星。

2.and we hope to prevent 4.2 million premature deaths by keeping immunization rates high over the next five years for basic immunization and rolling out vaccines against pneumonia and rotavirus diarrhea.

roll out铺开; 碾平

例句：They rolled out the red carpet for the guests.
      他们铺开红地毯迎接客人。

      Spread some flour on the table and roll the pastry out very thin.
      在桌上撒些面粉并把面皮弄得薄一点。

滔滔不绝地讲出来; 发出洪亮的声音

例句：The speech rolled out from his lips.
      他滔滔不绝地演讲。

3.What we wanted to test is whether it would be better to start first with good quality chest compressions to prepare the heart for this electrical shock -- to get some blood circulation to the brain and heart before we apply the shock."

What引导名词性从句

what引导从句的情况无处不在。

一.引导主语从句

　　1)What we need is more time.(what做need的宾语)我们所需要的是更多的时间.2)Whatreally matters is that she wore a pair of  white shoes.(what做matters的主语)真正麻烦的是她穿了一双白鞋.

　　二.引导宾语从句

　　1)People were perhaps more honest a long time ago when life was very different from what it is today.(what做从句中is的表语)很久以前当生活与现在的生活完全不同时，人们或许更诚实.2)People have heard what the President has said;they are waiting to see what he willdo.(what分别做动词heard和see的宾语)人们已经听到了总统所说的；他们正等着看总统会做什么.

　　三.引导表语从句

　　1)Whether ways will be found to stop pollution or not is just what worries the public.(what做从句中的主语)是否能找到阻止污染的方法就是所令民众担心的事儿.2)Thatiswhat I want to tell you.(what做从句中的宾语)那就是我想告诉你的事儿.3)The little girlis no longer what she used tobe.(what做从句中的表语)这个小女孩不再是过去的样子了.

　　四.引导同位语从句

　　1)They have no idea at all what he is working on.(what做从句的宾语)他们一点儿都不知道他正在做什么.2)You have no idea what I suffered.(what做从句的宾语)你不知道我所遭受的痛苦.通过以上例句及解释我们可以得出：what常用来引导名词性从句，即主语从句，宾语从句，表语从句和同位语从句.what在引导名词性从句时有两个重要的特点：一是它在相应的名词性从句中一定有含义，常表示“什么”，“所…的”，“…的样子”等.二是它在相应的名词性从句中一定做成分，而且常做主语，宾语或表语.