它们中的大部分都发生于暴露于紫外线的未加保护的皮肤。

The majority of them result from unprotected skin exposure to UV radiation.

youdao

因此，对于未加保护的水源，你必须采用过滤、化学处理或是烧开后再饮用。

Therefore, always filter, chemically treat or boil water you've taken from an unprotected source.

youdao

虽然您可以通过未加密的通道发送ltpa令牌，但是为了最大程度地加以保护，最好通过加密链接发送它们。

While you can transmit LTPA tokens over an unencrypted channel, for maximum protection, it is best that they are sent over an encrypted link.

youdao