Explain why this restriction is necessary for recursive descent parsing.

There are two restrictions on the type of grammars that can be used with a recursive descent parser. The first is that the grammar cannot have any left recursive productions. Give an example of a left-recursive production and explain why such productions would be a problem.
The second restriction is that the grammar must not require more than one token look ahead. Give an example of a production that does not have this property. Explain why this restriction is necessary for recursive descent parsing.