Who wrote the Mishna, and when? Who wrote the Gemara, and when? What is the difference between the Mishna and the Gemara?

It is customary to study Torah on Shavuot night. Does it make any difference what a person studies?

Dear Rabbi, After a long time I am again. In ISLAM there is a ritual of sacrificing animal like Camel, Cow, Goat, Dumba, Sheep once in a year in the Eid-Ul-Azha. Is there anything like that for jew? And is it mandatory ? And if so when and for which background? Is there anyone like Pope in Jew? If so Who is he and where does he live? I want his/her contact address. I like you and your community. Thank You Shamim

Dear Rabbi, Why is Shavuot only one day (two in the Diaspora) as opposed to Passover and Succot? Isn't it a very inportant celebration of giving us the Torah? Thanks

Hi my names is Arthur. I have a question regarding the Shabbat. 1.G-d said that we have to keep the shabbat. we have to rest the land has to rest and the animals have to rest. yes or no 2. Now if we work on our farm land we have to work six years and on the seven let the earth rest. yes or no Now if I start working on my land this year, but my neighbor will for reasons of his own will work on his land next year for the first time. Now my seventh year and is seventh year will be different but the land will have rest still on the seven day. No with that being said if I have a day off on a Tue but not a Saturday I still have my day of rest just not on a Saturday I still keep that one day just not on a Saturday. Yes, or no. Doesn't the day of rest means that you should rest one day a week not work so you could relax and get energy?