Which statement best describes why the bridge buckles when there isn't a joint ? a. Temperature causes expansion and contraction of the roadway, which is limited without a joint

b. The metal in the joint is not affected by temperature, so without it bridges buckle

c. The material of the roadway doesn't expand under temperature

d. Joints increase the strength of the roadway to prevent the weight of cars and trucks from causing the bridge to buckle

a

Explanation:

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photocells convert light energy to electricity

the word that best describes martin luther king jr.'s tone in the video is dignified

martin luther king, jr. was a social activist and baptist minister who played a key role in the american civil rights movement from the mid-1950s until his assassination in 1968. the video shows his manner and attitude having or showing a composed or serious manner that is worthy of respect so dignified is the correct answer