短语讲解：
1. In clinical trials at Johns Hopkins Cancer Center in Baltimore, Maryland, doctors report they successfully pumped cancer-fighting medicine directly into a breast tumor.
pump into注入，灌输
例句：A tyre expands when you pump air into it
轮胎一打气就鼓起来.
2. The clinical trials have been so promising that this type of treatment might eventually become the standard for patients with very early stages of breast cancer or those who are at risk of developing it.
at risk有危险
例句：The disease is spreading, and all children under five are at risk.
这疾病在蔓延, 五岁以下的小孩都有危险。
3. Dr. Sterns said researchers need to find out how much of the drug is needed and how often it should be administered to rid the breast of cancer.
find out发现, 看穿, 揭发, 找出;查明
例句：We must find out the truth of the matter.
我们必须弄清楚事情的真相。
rid of使摆脱
例句：You must rid yourself of this gloomy mood.
你必须使自己摆脱这种闷闷不乐的忧郁情绪。
