题干

降雪量是用一定面积的雪化成水后的高度来衡量的,一场大雪后,小华用刻度尺测出水平地面雪的厚度为185mm,然后他脚使劲将雪踏实,测出脚踩出的雪坑的深度为163mm,这场大雪的降雪量为(   )(雪踏实后,密度接近水的密度)

A:348mm

B:185mm

C:22mm

D:163mm

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答案(点此获取答案解析)

C

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    Thirteen-year-old American Jessica Goldstone wants to be a fashion designer when she finishes school. She thinks her designs would be more exciting than clothes bought from stores. But until this month, Jessica has never touched a sewing machine(缝纫机).

    After her first class, Jessica and six other girls aged 9 to 13 said that sewing was fun, cool and challenging.

    These students at Fabrics' Sew Fun class show that the sewing machine is becoming popular again.

    “There have been a lot of teens getting excited about sewing,” said a sewing company worker Donna Smith. “Some of them come from the Project Runway TV show,” she said. This TV show is an exciting weekly contest to make a great fashion designer. Every week one contestant (参赛者) fails the test and has to leave the contest.

    The number of people who joined sewing class summer camps grew by 10 percent this year. That's good news for companies that make sewing machines and publish sewing magazines. The Singer Sewing Company sold nearly 3 million sewing machines in the United States last year. This is about twice as many as in 1999.

    Sewing machines have been around for more than 150 years, but they have changed a lot since your grandmother was a girl.

    Spencer Carmel started sewing lessons after getting a sewing machine for her 11th birthday. She has sewn a lot by hand, but she wants to make more difficult things. Spencer's class recently made hats.

    Another member of the class, Kelsey Oen, 9 years old, needed time to get used to her machine, but soon she could use it well. By the end of the class, Kelsey was happy and wearing her new hat.