Yī / shēng / gěi / tā / kāi / le / xiāo / suān / gān / yóu / yǐ / bèi / xīn / jiǎo / tòng / fā / zuò / shí / shǐ / yòng

医生给他开了硝酸甘油，以备心绞痛发作时使用。

The doctor prescribed nitroglycerin for him to use in case of an angina attack.