How do you say "Who is this?" or "Who is that?" in Japanese?

How do you say the following in Japanese?

• Which one is mine? That one is yours. Is this a Japanese book? No, that isn't a Japanese book. I've just started taking Japanese seriously and I left my notes at school >.< Also, Hiragana for the following would be appreciated as well. What is that over there? That is a rice cracker. What is this? This is Japanese tea. Is this a Japanese car? That is a Japanese book. Which one is a Japanese car? This is very delicious. That (near you) is a delicious cake.

• Answer:

  Which one is mine? どれがわたし（ぼく）のですか？ That one is yours. あれ（それ）があなたのです。 Is this a Japanese book? これは、にほんごの　ほんですか？ No, that isn't a Japanese book. いいえ、それは、にほんごの　ほんでは ありません。 What is that over there? あそこにあるのは、なんですか？ That is a rice cracker. あれはせんべいです。 What is this? これはなんですか？ This is Japanese tea. これは、にほんちゃ　です。 Is this a Japanese car? これは、にほんしゃ　(にほんせいのくるま） ですか？ That is a Japanese book. それ（あれ）は、にほんごの　ほんです。 Which one is a Japanese car? どれが、にほんしゃ　（にほんせいのくるま） ですか？ This is very delicious. これは、とても　おいしいです。 That (near you) is a delicious cake. それは　おいしい　けーき　です。 Good luck!!