The medicine is effective against cancer.是什么意思？

The medicine is effective against cancer.

这药物治癌有效。

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

medicine

n. 医学，药物，有功效的东西，良药；

例句
Modern medicine has a large armoury of drugs for the treatment of mental illness.
现代医学有大量可以用来治疗精神疾病的药物。

is

vt.& vi. 是（be的三单形式；n. 存在；

例句
Bollinger 'RD' is a rare, highly prized wine.
博林格RD香槟是一种名贵的备受推崇的葡萄酒。

effective

adj. 有效的，起作用的，实际的，实在的，给人深刻印象；n. [军]现役兵额，有生力量，精兵；

例句
Light colours provide an effective backdrop for pictures or a mirror.
浅色是挂放图画或镜子很有效果的衬托。

against

prep. 反对，对…不利，紧靠，以防；

例句
His hand brushed against hers; it could have been either accidental or deliberate.
就在有意无意间，他的手轻轻拂过她的手。

cancer

n. 癌症，恶性肿瘤，弊病，社会恶习，迅速蔓延的恶劣的或危险的事物，[天]巨蟹座，巨蟹宫；

例句
An increasing body of evidence suggests that all of us have cancer cells in our bodies at times during our lives.
越来越多的证据表明，我们所有人一生中体内时有癌细胞存在。