For some countries, you have to be vaccinated against some diseases such as small pox and yellow fever.
For some countries, you have to be vaccinated against some diseases such as small pox and yellow fever.
有些国家入境时则要求接种一些疾病的疫苗，例如天花和黄热病。
For some countries, you have to be vaccinated against some diseases such as small pox and yellow fever.
有些国家入境时则要求接种一些疾病的疫苗，例如天花和黄热病。