Step-by-step reasoning process: Hippos are large and have large teeth. If threatened, they aggressively defend themselves.
[Q and A]: Are hippos dangerous to humans?
yes

Step-by-step reasoning process: Call waiting was invented in the 1970's to allow phone users to suspend one call to accept another. Alexander Graham Bell's phone was used in 1876.
[Q and A]: Did the phone Alexander Graham Bell use have call waiting?
no

Step-by-step reasoning process: Tostones are a Latin American twice fried dish made of plantains. Plantains resemble bananas, but are not bananas.
[Q and A]:
Would you buy bananas for tostones?
no