plant problems

I am suprised no one has replyed to my question on my plant.. 
It's not helping. One that started about 3 or 4 days ago is now 
out of the water. The tank isn't full but the water is only an 
inch or 2 below the top. Only one has little leaves on it. The 
long one doesn't. I will bring it tommorow and float it in one 
of the biology tanks until your class or if you have a lunch 
tommorow i will bring it in then. It really has me puzzled. I 
have no idea how it got there. All i hagve in the tank is a ugf 
and gravel, which was taken from the pet store, washed and 
immediatley put in the tank. If you can help email me.

Please help,