Please help me with these three questions

1)consider the following code snippet: #ifndef book_h#define book_hconst double max_cost = 1000.0; class book{public: book(); book(double new_cost); void set_cost(double new_cost); double get_cost() const; private: double cost; }; double calculate_terms(book bk); #endifwhich of the following is correct? a)the header file is correct as given. b)the definition of max_cost should be removed since header files should not contain constants. c)the definition of book should be removed since header files should not contain class definitions. d)the body of the calculate_terms function should be added to the header file.

How do you take a green screen out of the video while editing?

1. web and mobile applications allow users to be actively engaged in an online activity. a true b false 2. some examples of business applications purposes are to collaborate, share files, meet virtually in real-time, and accept payments. a true b false 3. an education application would most likely do which of the following? a allow users to watch popular movies and tv shows b connect users with social and business contacts c confirm users' travel plans d teach users a new language 4. a uniform resource locator (url) is how the internet knows where to take users when an address is typed into a browser. a true b false 5. deon is required to provide the citation information for his sources. what type of information should he collect from his sources? a author name, title, date of publication, date of access, url b connections to background information c interesting facts and statistics d notes on important information