因为:
1. because
2. owing to
3. on account of
Relative explainations:
<by reason that> <because of> <for as much as> <for> <inasmuch> <in respect that> <as> <what with> <that> <insomuch as> <inasmuch as> <being that> <for reasons of> <one reason or another> <by occasion of> <by reason of>
Examples:
1. 我因为追赶公共汽车，弄得上气不接下气。
I was out of breath after running for the bus.
2. 他之所以成功是因为他工作勤奋。
He achieved because he was a hard worker.
3. 这门开起来很容易，因为合页上了油。
The door opens easily because the hinges were oiled.
4. 她和丈夫离婚了，因为她发现他是个酒鬼。
She divorced with her husband because she found him a drunkard.
5. 我知道她是在开玩笑，因为她脸上堆满笑容。
I knew she was joking because she had a big grin on her face.
6. 这个小女孩因为斜视不敢在公共场合露面。
The little girl dares not to appear in public because she is cross-eyed.
7. 这名记者因为试图揭露一个阴谋而被杀害。
The reporter was killed because he tried to expose a plot.
8. 因为现在是收获期，所以我们都非常忙。
We are all very busy because it's the harvest time.
Inasmuch as; since.
因为；由于
Capable of being attributed.
因为…引起的
The answer is:
这是因为：
For as much as
因为，由于；既然
Because I am sick.
因为我生病了。
Because it is raining.
因为天在下雨。
Because it's too heavy.
因为太重了。
Because it's rain.
因为天在下雨。
Because I have no time.
因为我没有时间。
a mistake resulting from neglect.
因为忽视产生的错误。