I'm not happy, because I have no birthday cake.

因为我没有生日蛋糕。

youdao

I don't know how bad the injury is, because I have never had one like this before.

我不知道伤势有多重，因为我以前从未受过这样的伤。

《柯林斯英汉双解大词典》

I have not worried so much this year, partly because I have had other things to think about.

今年我不那么担心了，在一定程度上是因为我还有其他的事情要考虑。

《柯林斯英汉双解大词典》

Madam C.J.Walker explained it this way: "If I have accomplished anything in life, it is because I have been willing to work hard."

VOA: special.2010.03.28

And notice because I have just one line of code inside of each of these branches, what have I clearly omitted?

请注意因为我在每个分支中只有一行代码,显然地我省略了什么？

哈佛公开课 - 计算机科学课程节选

because I have to walk a really long way from the subway to get to the Yoga studio.

因为我从地铁到瑜伽工作室要走很长的一段路。

上东区的氛围 - SpeakingMax英语口语达人

Because I have no idea how to explain "Livin' La Vida Loca" to a child.

CNN: Apparently This Matters: Kidz Bop and 'Call Me Maybe'

And I would like to go, because I have friends, I have family and everything.

NPR: Miami's Cuban Exile Community Evolves Again

And I can say this because I have seen it happen in myself and countless others.

CNN: From miserable man to 'Ultraman': A fitness journey