質問がある！

[heilong-gou]

１．）(for those who have been to China)
万里の長城か故宮博物院に行ったことがありますか。

２．）(for those who have been to Great Britain)
大英図書館か大英博物館に行ったことがありますか。

３．）
Which would be more formal when addressing a male master?
先生, 師父, or お師匠様 ?

and 4.)(for those familiar with Buddhist deities)
What's a vajra and its purpose? ( I think a vajra is also known as 金剛 . )

ありがとう！
From 黒龍号　（ヘイロンごう）

[CviCvraeVtMoriar]

Vajra is a Sankrit word which means "lightning" or "thunderbolt". I think that the god Indra wields it or something.

Vajrayana is one of the primary branches of Buddhism.