Read the paragraphs from “The First Electric Light Show” by the Museum of Technology, then answer the question that follows.

(3) In 1879, inventors began experimenting with ways to use electricity to entertain large crowds. One inventor, Charles Brush, designed an “arc lamp,” a powerful light that could shine brighter than anything people had seen before. Cities used Brush’s lamps for nighttime street fairs and holiday celebrations, and the bright glow quickly became a source of wonder.

(4) As the excitement grew, Brush improved his lamps to make the light steadier and easier to control. He created new devices that allowed the lamps to flash, dim, or brighten on command. These improvements made it possible to design dramatic nighttime “light shows,” drawing even bigger crowds who wanted to see the new electric spectacles.

QUESTION:
Which idea is introduced in paragraph 3 and further developed in paragraph 4?

Read the paragraphs from “Motion Pictures” by the National Park Service, then answer the question that follows.

 (3) Around 1889 Edison picked a team of muckers to work on this project, headed by William Kennedy Laurie Dickson. They built the Strip Kinetograph, which was a very early movie camera. The "strip" was a piece of long, flexible film that had been invented for a regular camera. Unlike older photographic film, it could be wrapped around a wheel or a spool. The Strip Kinetograph took pictures so fast that they would seem to move. 

(4) Then Edison and his muckers built a Kinetoscope, a machine to watch these movies. One person at a time would pay five cents to watch a short, silent movie about twenty to thirty seconds long. The first Kinetoscope parlor, or movie theater, opened on April 14, 1894, at 1155 Broadway in New York City.

 Which idea is introduced in paragraph 3 and further developed in paragraph 4? 

Read the paragraphs from “Early Flight Experiments” by the Aeronautical History Foundation, then answer the question that follows.

(3) Before airplanes existed, many scientists studied how birds moved their wings. Engineer Otto Lilienthal believed that humans could glide through the air by copying those natural wing movements. He built several gliders made of wood and fabric, testing them on small hills to see how long he could stay in the air. His early flights were short and unsteady, but they proved that controlled human flight might be possible.

(4) Over time, Lilienthal adjusted his glider designs to improve stability. He experimented with curved wings, lighter materials, and new steering systems that allowed the pilot to shift their weight in midair. These innovations helped Lilienthal glide farther and with more control, inspiring future inventors—including the Wright brothers—to pursue powered flight. His work showed how careful improvements could transform a simple idea into a revolutionary technology.