Immune system: lymph nodes ; ; excretory system: a. kidneys b. blood c. bladder d. urine

Kidney would be the best answer here.

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did you mean: energy is defined ashyperactivitya caloric measurementthe ability to move matterthe ability to think and analyze this form of energy is called "energy in motion" or "energy of moving matter"potential energy kinetic energy electrical energy1 ptlights on a stage can be examples of all of the following forms of energy exceptelectrical energylight energythermal energysound energywhen one type of energy changes to another this is called energy energy is stored based on their position or shape this is called energy.kinetic potential sound electromagnetic