1.She's from (China).(对括号里的提问)
Where is she from?(=Where does she come from?)
2.My father is a (policeman).(对括号里的提问)
What is your father?(=What do your father do?=What is your father's job?)
3.There is (a) ball under the desk.(对括号里的提问)
How many balls are there under the desk?