VOA慢速英语:Hospital Infections in US Continue to Rise

1.In the United States alone, the number of infections in hospitals is estimated at close to two million each year.

close to离…近

例句：His house is close to mine.
      他的房子靠近我家。

      It is close to fact.
      这更接近于事实。

2.A new government report notes that very little progress has been made in reducing what are called health care-associated infections.

little做形容词表达否定的含义。而Little还可以做副词：

1)little better：其意为“好不了多少”，相当于not much better。如：

His second suggestion was little better than his first. 他的第二条建议比第一条好不了多少。

His legs were in little better shape than they had been the year before. 他的双腿与前一年相比没有多少好转。

2)little more (than)：其意为“只”“只不过”。如：

He was little more than a child when his father died. 他父亲去世时，他差不多还是个孩子。

Aid to the Third World is at present little more than a drop in the ocean. 目前对第三世界的援助不过是杯水车薪。

He left school with little more than a basic education. 他只接受了点基础教育就退学了。

3.Many infections have been increasing even as hospitals have made efforts to improve.

have been increasing是现在完成进行时

表示从过去某时开始一直延续到说话时还在进行，或可能还要继续下去的动作。它通常和“for+段时间”或“since+点时间(也可以是从句)”的时间状语连用。例如：

I have been waiting for a letter from my parents.　我一直在等我父母的来信。
It has been raining for three hours.　
雨已经下了三个小时了。
We have been studying here since 2004.
自从2004年以来，我们一直在这里学习。

表示从过去某时开始，一直延续到说话时刻，可能刚刚结束的动作。例如：

She has been sweeping the street all day. She is too tired.
她一整天都在扫大街。她太累了。

We have been waiting for you for two hours. We don't want to wait any longer.
我们已经等你两个小时了。不想再等了。

4.It says catheters should be used only if necessary.

only if表示"只有"；if only则表示"如果……就好了"。If only也可用于陈述语气。
　　I wake up only if the alarm clock rings. 只有闹钟响了，我才会醒。
　　If only the alarm clock had rung.　　　当时闹钟响了，就好了。
　　If only he comes early.　　　　　　　但愿他早点回来。