1. There are few dictionary mistakes in this book.

Detailed explanation

There are many examples

4. Does the library need to buy it?

5. There is too much time.

To be honest, it's a waste of time.

7. Many times an electronic dictionary is enough, but sometimes if words have many meanings, you need to use a dictionary book.

Sometimes the dictionary doesn't contain everything, such as slang, so you need to look it up online.