Translate the following underlined sentences into Chinese.
The past few centuries have witnessed balloon's expansion into various aspects of life. While small balloons are used as colorful decorations, scientists use weather balloons to collect meteorological data from the atmosphere.
Balloons are even used by doctors to “inflate” the blood vessels of patients to aid in circulation.【正确答案】：
医生甚至用气球来“扩张”病人血管，改善血液循环。 
【题目解析】：本题主要考查inflate的理解与翻译。inflate：v. 给…充气；使大幅增加；使极度增长；膨胀；夸大；胀大；夸张；使…膨胀。本句中inflate的宾语是 blood vessels“血管”，所以可以意译为“使血管膨胀，扩张血管”。aid in：有助于；circulation：循环
