kaze ga tsuyoi desu kara, doa o shimete mo ii desu ka.

to be

Breakdown of kaze ga tsuyoi desu kara, doa o shimete mo ii desu ka.

• を: direct object particle
• か: question particle
• が: subject particle

Questions & Answers about kaze ga tsuyoi desu kara, doa o shimete mo ii desu ka.

Why is が used after 風 instead of は?

In this sentence が marks 風 as the subject that’s giving new information (“the wind is strong”). Using は would make 風 the topic (“as for the wind…”), which can feel more like setting the scene. Here, が simply states the fact that the wind is strong, establishing the cause.

Can we omit です in 強いですから and just say 強いから?

Yes. Since 強い is an い-adjective, you can attach から directly to its dictionary form:
風が強いからドアを閉めてもいいですか？
This still sounds polite because of いいですか. However, keeping 強いですから makes both clauses uniformly polite.

What’s the difference between ですから and だから when connecting clauses?

だから attaches to plain forms and is casual. ですから is the polite counterpart, attaching to statements ending in です (or polite noun/な-adjective forms). In formal or polite speech, you’ll choose ですから.

Could I use ので instead of から to express the cause here?

Absolutely. ので often sounds softer or more formal than から. You’d say:
風が強いのでドアを閉めてもいいですか？
Both から and ので work to express “because.”