(14) he also replaced the common steel wheels with clay ones. (15) stevenson, however, did not stop there…

(14) he also replaced the common steel wheels with clay ones. (15) stevenson, however, did not stop there. (16) he also transformed skateboarding with his addition of the kicktail. (17) a kicktail is the curved section on the back of the board, which allows skateboards to fly. (18) with these improvements, they now had more control and could perform aerial stunts. (19) not satisfied with stevensons use of clay wheels, frank nasworthy stumbled upon the idea to use urethane wheels. (20) urethane is commonly found in the midsoles of athletic shoes. (21) nasworthys wheels allowed the skateboards to better grip surfaces and provided the additional benefit of more control. (22) both stevensons and nasworthys contributions in the 70s revolutionized skateboarding. (23) their contributions saved it from the brink of extinction and placed it in the mainstream as municipalities became dotted with skate parks. (24) skateboardings popularity, however, would fall again due to safety concerns as many skate parks could not afford the insurance premiums needed to protect themselves and the skaters who used their parks. (25) despite this setback, skateboarding did not disappear; it just went underground. (26) skateboarding soon became a subculture of the youth, gaining popularity as documentary - style, straight - to - video films launched the careers of many who are now household names. (27) these videos paved the way for the 6. which sentence is extraneous and should be deleted from the fourth paragraph (sentences 19 - 24)? sentence 19 sentence 20 sentence 21 sentence 22 clear all

(14) he also replaced the common steel wheels with clay ones. (15) stevenson, however, did not stop there. (16) he also transformed skateboarding with his addition of the kicktail. (17) a kicktail is the curved section on the back of the board, which allows skateboards to fly. (18) with these improvements, they now had more control and could perform aerial stunts. (19) not satisfied with stevensons use of clay wheels, frank nasworthy stumbled upon the idea to use urethane wheels. (20) urethane is commonly found in the midsoles of athletic shoes. (21) nasworthys wheels allowed the skateboards to better grip surfaces and provided the additional benefit of more control. (22) both stevensons and nasworthys contributions in the 70s revolutionized skateboarding. (23) their contributions saved it from the brink of extinction and placed it in the mainstream as municipalities became dotted with skate parks. (24) skateboardings popularity, however, would fall again due to safety concerns as many skate parks could not afford the insurance premiums needed to protect themselves and the skaters who used their parks. (25) despite this setback, skateboarding did not disappear; it just went underground. (26) skateboarding soon became a subculture of the youth, gaining popularity as documentary - style, straight - to - video films launched the careers of many who are now household names. (27) these videos paved the way for the 6. which sentence is extraneous and should be deleted from the fourth paragraph (sentences 19 - 24)? sentence 19 sentence 20 sentence 21 sentence 22 clear all

Answer

Brief Explanations:

The paragraph focuses on the contributions of Stevenson and Nasworthy to skateboarding and its mainstreaming. Sentence 20 provides a detail about urethane being in the midsoles of athletic shoes, which is off - topic from the main narrative about skateboarding improvements and its popularity trajectory.

Answer:

Sentence 20