complete book

I can complete a book in 30 days.The part of the book that I can complete in 20 days

I can complete a book in 30 days.The part of the book that I can complete in 20 days

Select the most appropriate option to substitute the underlined segment in the given sentence.If there is no need to substitute it, select No improvement. He have been working on and off for two years to complete a book.

Take down this diagrams, Fig. on to your answer book and complete the path of the rays.