Work done in both negative and positive conditions is considered to be work done. Explanation is given below:

• Yes, work is done, but it is negative because Suma is pushing water backward.
• No, the work is not done, because the donkey is standing and the load placed on it's back is perpendicular to the horizontal displacement.
• Yes, work is done, because the water is being lifted against the force of gravity.
• No, work is done, because the leaves of the plant are in rest.
• Yes, it is working, because the engine is pulling the train and the wagons are being displaced in the same direction.
• No, because the grains are at rest.
• Yes, the work is done, because the wind is pushing the sail-boat in favorable directions.