yī
咱们是一家人
zánmen shì yījiārén
We are family
这不是一码事。
zhè bú shì yī mǎ shì
This is not the same thing / These are two different matters
番茄一名西红柿。
fānqié yī míng xīhóngshì
Tomato, also known as western red persimmon