When you have difficulty in learning English,you can ask yo

When you have difficulty in learning English,you can ask yo
19.When you have difficulty in learning English,you can ask your teacher for some ____.
A information B advices C advice D advices
20.----Have you considered ___ your job?
----No,I consider my job ____interesting .
A to change,to be B to be changing,as
C changing,being D changing,/
21.Charles Babbage is generally considered ___ the first computer.
A to invent B inventing
C to have invented D having invented
选什么?为什么