The complete prepositional phrase in the sentence stated above is "in the door's key hole". As the name suggests, this type of phrase is introduced by prepositions which in this case is with the use of preposition "in". It answers the question "where" which refers to the location of the object it modifies.
Answer: yes
Explanation: I would like to have a large family
because , i would be successful & go to college and i wouldn't want to just have 1 kids or 2 i would like to have 3 and i would want 1 daughter and 2 sons !
You can write "In the sinking of the Titanic which were the most significant(big) in causing the devasting loss of life?"
Answer:
"Harry now had a companion in the form of his owl, and he decided to call her Hedwig."