I download the Ganache on Windows, it gives me 10 accounts and 12 mnemonics when I launch it, I think that the first 10 mnemonics are represent for 10 accounts, but what are the other 2 mnemonics "subway" and "mouse" represent for? I cant catch that...so can anybody help me about this? Thanks!
In fact those 12 words are 1 mnemonics used to generate those 10 accounts.
They are following the BIP 44 (Multi-Account Hierarchy for Deterministic Wallets) specification which is the same for a lot of blockchain.
You can see a bit more how it works here just enter your 12 words as mnemonics and see how are generated multiple accounts with it