Broad
large from one side to the other，wide 宽的，宽阔的，广阔的 [形容词]
1. He had broad shoulders and powerful arms.
他肩膀宽大，双臂有力。
2. Our country is a big agricultural country with a broad area and a large number of population.
我国是一个幅员辽阔，人口众多的农业大国。
3. He is tall，broad and muscular.
他身高肩宽，肌肉发达。
Abroad
in or to a foreign country 在国外；去国外 [副词]
1. She worked abroad for a year.
她在国外工作了一年。
2. Millions of Chinese students and tourists travel abroad each year.
每年有数百万的中国学生与观光客到国外旅行。
3. Most of my friends live abroad.
我的朋友大多数住在国外。
【注意】
1. 请注意broad与abroad词性的不同。broad主要用作形容词，abroad主要用作副词。
2. 请注意broad比较级和最高级的形式：broad - broader - broadest