题干

下列各表述与示意图一致的是(  )

A:图①表示25℃时,用0.1 mol•L﹣1盐酸滴定20 mL 0.1 mol•L﹣1 NaOH溶液,溶液的p随加入酸体积的变化

B:图②中曲线表示反应2SO2(g)+O2(g)⇌2SO3(g)△H<0正、逆反应的平衡常数K随温度的变化

C:图③表示10 mL 0.01 mol•L﹣1 KMnO4酸性溶液与过量的0.1 mol•L﹣1 H2C2O4溶液混合时,n(Mn2+)随时间的变化

D:图④中a、b曲线分别表示反应CH2═CH2(g)+H2(g)→CH3CH3(g)△H<0使用和未使用催化剂时,反应过程中的能量变化

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答案(点此获取答案解析)

B

同类题3

阅读下列短文,从每题所给的 A、B、C、D 四个选项中,选出最佳选项,并在答题卡上将该项涂黑。
A
    It was a cold March day in High Point, North Carolina. The girls on the Wesleyan Academy softball were waiting for their next turns at bat during practice, stamping their feet to stay warm. Eighth-grader Taylor Bisbee shivered(发抖) a little as she watched her teammate Paris White play. The two didn't know each other well —Taylor had just moved to town a month or so before.
    Suddenly, Paris fell to the ground,“Paris's eye rolled back,” Taylor says. “She started shaking . I knew it was an emergency.”
    It certainly was, Paris had suffered a sudden heart failure. Without immediate medical care, Paris would die. At first,no one moved. The girls were  in shock. Then the softball coach shouted out, “Does anyone know CPR?”
    CPR is a life-saving technique. To do CPR, you press on the sick person's chest so that blood moves through the body and takes oxygen to organs. Without oxygen the brain is damaging quickly.
    Amazingly, Taylor had just taken a CPR course the day before. Still, she hesitated. She didn't think she knew it well enough. But when no one else came forward, Taylor ran to Paris and began doing CPR, “It was scary. I knew it was the difference between life and death,” says Taylor.
    Taylor's swift action helped her teammates calm down. One girl called 911. Two more ran to get the school nurse, who brought a defibrillator, an electronic devices(器械) that can shock the heart back into work. Luck stayed with them: Paris' heartbeat returned.
     “I know I was really lucky,” Paris say now. “Most people don't survive this. My team saved my life”
    Experts say Paris is right: For a sudden heart failure, the single best chance for survival is having someone nearby step in and do CPR quickly.
    Today, Paris is back on the softball team. Taylor will apply to college soon. She wants to be a nurse. “I feel more confident in my actions now,” Taylor says. “I know I can act under pressure in a scary situation.”