Are the underlined parts of these sentences OK? Correct them where necessary

3 How many plays has William Shakespeare written? 

4 I’ve forgotten his name. Is it Joe or Jack? 

5 Who has invented paper? 

6 Drugs have become a big problem everywhere. 

7 We’ve washed the car, but now it’s dirty again. 

8 Where have you been born? 

9 Ellie has gone shopping. She’ll be back in about an hour. 

10 Albert Einstein has been the scientist who 

has developed the theory of relativity.