In what ways are the following expressions structurally ambiguous?

In what ways are the following expressions structurally ambiguous? Draw all the possible tree diagrams associated with each of them:

a. An American history teacher.

b. Flying planes can be dangerous.

c. They have wounded people there.

d. Leslie is the son of Frank’s daughter.

e. The parents of the groom and the bride were waiting. 

Example: An American history teacher.

• [[AmericanA historyN]Nˈ teacherN]N] ‘teacher of American history’
•  [AmericanA [hístoryN teacherN]N]Nˈ ‘American teacher of history’