An IEntityDrop refers to a drop from an Entity.

It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import.
import crafttweaker.entity.IEntityDrop;

You can retrieve this information out of them.

ZenGetter	功能	Return type	Usage
ZenGetter chance	功能 Returns the chance of the drop.	Return type float	Usage drop.chance
ZenGetter max	功能 Returns the maximum Amount of the drop.	Return type int	Usage drop.max
ZenGetter min	功能 Returns the minimum Amount of the drop.	Return type int	Usage drop.min
ZenGetter playerOnly	功能 Returns whether the drop is playerOnly.	Return type 布尔值	Usage drop.playerOnly
ZenGetter range	功能 Returns the minimum to maximum Amount range of the drop.	Return type IntegerRange	Usage drop.range
ZenGetter 堆叠	功能 Returns the dropped Item.	Return type IItemstack	Usage drop.stack