Given a scientific passage and an answer, generate a question for the given answer.

Passage: tobacco smoke causes fatal lung disease in nonsmokers. Answer: tobacco smoke
What still causes fatal lung disease in nonsmokers?

Passage: The jointed appendages of arthropods may be used as legs for walking. Being jointed makes them more flexible. Try walking or climbing stairs without bending your knees, and you'll see why joints are helpful. In most arthropods, the appendages on the head have been modified for other functions. Figure below shows some of the head appendages found in arthropods. Sensory organs such as eyes are also found on the head. Answer: walking
What may the jointed appendages of arthropods be used for?

Passage: Skin protects the body from injury, water loss, and microorganisms. It also plays a major role in maintaining a stable body temperature. Answer: skin
Which organ protects the body from injury, water loss, and microorganisms?