阅读短文，判断正(T)误(F)。
Bob's little sister is five years old. She is always asking questions. She wants to know why a car must have
wheels, what is inside a tree and even how the moon stays in the sky without falling. Bob tries to give her the
correct answers. However, sometimes even his parents don't know the answers. His father gets some books
from the library and reads them to find the answers. His mother says that she learns many interesting things
when her children ask questions. She is very happy. But she still doesn't know the answers to some of the
questions.
( ) 1. Bob is always asking questions.
( ) 2. Bob tries to give his sister the correct answers.
( ) 3. His parents know all the answers to the questions.
( ) 4. His father reads books to find the answers.
( ) 5. Bob's mother is very happy to learn many interesting things.