Task: Paraphrasing
Input (English): Question: Which body system typically recognizes, attacks, and destroys foreign cells or substances that may cause disease? 
Answer: immune. 
Sentence: The immune system typically recognizes, attacks, and destroys foreign cells or substances that may cause disease.
Output (English): When foreign cells or substances get into the body, the organism's immune system first needs to be able to recognize the foreign cell/substance.  Then it can mount an appropriate attack.