地理差异是该疾病最显著的特点之一，北部国家如加拿大和斯堪的纳维亚发病比较普遍，而靠近赤道的国家最低。

Geographical variation is one of the most striking features of the condition - it is most common in northern countries such as Canada and Scandinavia and lowest in countries near the equator.

youdao

地理差异是该疾病最显著的特点之一，北部国家如加拿大和斯堪的纳维亚发病比较普遍，而靠近赤道的国家最低。

Geographical variation is one of the most striking features of the condition - it is most common in northern countries such as Canada and Scandinavia and lowest in countries near the equator.

youdao