This is Kitty. She is my sister.

这是基蒂。她是我的妹妹。

Of course she is my sister. Anybody can guess that too.

她当然是我的妹妹，这一点也是谁都猜得出来。

And Abraham said of Sarah his wife, She is my sister: and Abimelech king of Gerar sent, and took Sarah.

亚伯拉罕称他的妻撒拉为妹子，基拉耳王亚比米勒差人把撒拉取了去。