11. Whick ef doe following HTML can geserate dieck boxer? A) cirpul ope-4heck"? B) calieckbove D) celyeck? 12. Which of the following options bas correct cos5 spax? A) bobyeolor-black B) (body:color black(body) C body (color black) D) (bodycolorblack) 13. How to aAd a back ground color to all this elements? A) Ml.all (background-color-AFFFF) B) h1 (background-color:HFFFFF) C) all. hi (bockgound-odor FFFFF) D) hi (background:HFFFFF) 14. What in the correct lavaScript syntas for cutputting "Hello World" on the console? A) console loy('Hello World? B) "Hello World C document. write("Hello World") D) ("Hello World") 15. Output result of code frapment; console log(typeof (a=>1)); A. string B. function C. object D. string 16. The following JavaSenipt consuctor identifiers meet the best practice style ( ) a. A b. Pig c. dog d. 6 Chicken 17. Which of the following is the host of Javascript 0 a. Office b. Win 10 c. VS Code d. IE 18. In davacript you need to declare a variable ist of string type. Which of the following statements can achieve the above requirement? ( ) A.strifig str; B.conet str: C.let str; D. String str: 19. The following statements about code optimization are incorrect 0 A) After the Javascript program code is written, it is mainly left to the browser to run B) Use global variables as much as possible to simplify the code C) The writing style should follow the prineiples of "short identifier with clear meaning", "code indent alignment", "comnient as much as possible", ete D) The code raning oa the machine is expected to be as fast as possible, and its readability and understandability are the best during reading and mainterunce