The mass of a measuring cylinder when empty is 
. 
of liquid is poured into the measuring cylinder and the total mass of the measuring cylinder and the liquid is 
. Four solid objects are dropped into the liquid one after the other. The densities of the objects are shown below:
Which of the objects will float in the liquid?
1 only
1 and 2 only
1, 2 and 3 only
1, 2, 3 and 4.
