1.1. What did the boy do to get money?

A He worked in a hospital.

B He sold things door-to-door.

C He asked people for food.

D He acted as a doctor.

解析：选B。B细节理解题。原文第一句明确说明男孩通过挨家挨户卖东西赚钱（He sold things door-to-door for money）。故选B。

2.2. What did the girl give the boy?

A Water.

B Juice.

C Milk.

D Money.

解析：选C。C细节理解题。文中提到女孩给了他牛奶代替水（She gave him milk instead）。故选C。

3.3. Why did Dr. Kevin help the girl years later?

A He wanted to be famous.

B The girl was his sister.

C He wanted to thank her.

D The girl knew him well.

解析：选C。C细节理解题。根据文章内容可知，Dr. Kevin就是当年女孩帮助的的那个男孩，多年后，成为名医的男孩帮助女孩是为了回报她的善意。故选C。

4.4.What does “the poor boy” do now?

A A doctor.

B A milkman.

C A teacher.

D A driver.

解析：选A。A细节理解题。根据“Dr. Kevin was the boy she helped long ago!”可知，当年那个小男孩如今变成医生了。故选A。