How would I say "this is because," in japanese?

Question

i just don't think that これわそうだから、 is correct

Answer 1

You can get the sample sentence and the answer here:

I am sick. This is because I was drenched to the skin in a shower.

私｛わたし｝は具合｛ぐあい｝が悪｛わる｝い。というのはにわか雨｛あめ｝にあってずぶぬれになったからだ。

For the sentence "This is because ＊＊＊＊＊＊＊＊＊＊.", the general answer is as follows.

1. その理由は＊＊＊＊＊＊＊＊＊＊からだ。
2. その理由は＊＊＊＊＊＊＊＊＊＊からです。(polite form)
3. というのは＊＊＊＊＊＊＊＊＊＊からだ。
4. というのは＊＊＊＊＊＊＊＊＊＊からです。(polite form)