He probably is not used to reading much. The more well read the child is, the easier it is for them to do comprehensions. My advise would be to get him to read as much as possible which will incease his reading speed, vocabulary and understanding.
Secondly, start by doing any comprehensions, such as Bond, with your child. Read the the text together, then read the questions and see where he/she struggles, point him to the right answer, guide him how to find answers in the text, as answers are always in the text: explicitly or implicitly! Continue working together and gradually he/she should gain confidence to do it alone.