1 point 7. Why is putting "using namespace std;" at the beginning of a .cpp file is considered as a bad practice? * After putting the statement, programmers are required to type additional coding like "std:: "using namespace std;" should be put in a header file. It may pollute local namespace. The statement increase memory loading to the system. 1 point 8. What does a header file store? (Check all apply) * Class definition Constant definition Function declaration Actual operation of a function 1 point 9. If separation of files is adopted. what should main() do? The main() should focus only on defining actual operation of fuctions. The main() should focus only on defining signatures of functions. The main() should focus only on linking up all separated files. The main() should focus only on the coordination of different files to complete task(s). 1 point 10. If using namespace std;" is omitted, what could a programmer include when s/he wishes to show output on screen? (Check all apply) * Write using std::cout;" before *cout