问题 选择题

取等体积、等浓度的两份NaOH溶液,把其中一份A放在空气中一段时间,另一份B密封保存;用已知浓度的硫酸溶液中和上述两份溶液,若所消耗的硫酸溶液体积分别为VA和VB,则下列说法正确的是(  )

A.若用甲基橙作指示剂,VA>VB

B.若用甲基橙作指示剂,VA<VB

C.若用酚酞作指示剂,VA>VB

D.若用酚酞作指示剂,VA<VB

答案

答案:D

单项选择题

A

Little Tommy was doing very badly in math. His parents had tried everything—tutors (家庭教师), cards, special learning centers—in short, everything they could think of. Finally they took Tommy to a catholic (天主教) school.

After the first day, little Tommy came home with a very serious look on his face. He didn’t kiss his mother and say hello. Instead, he went straight to his room and started studying. Books and papers were spread (铺开) out all over the room and little Tommy was hard at work. His mother was surprised. She called him down to dinner and as soon as he finished eating, he went back to his room, without a word. In no time he was back hitting the books as hard as before. This went on for some time, day after day while the mother tried to understand what was happening.

Finally, little Tommy brought home his report card. He quietly put it on the table and went up to his room and hit the books. His room looked at it and to her surprise, little Tommy got an A in math. She could no longer hold her curiosity (好奇心). She went to his room and asked, "Son, what was it Was it the nuns (修女)"

Little Tommy looked at her and shook his head," No. "

"Well then," she asked again. "WHAT was it"

Little Tommy looked at her and said, "Well, on the first day of school, when I saw that man nailed (钉) to the plus sign (加号), I knew they weren’t joking. \

Tommy’s mother felt surprised that his son().

A.was still the same as usual

B.ate so much at dinner

C.kissed her and said hello after school

D.worked hard but said little

单项选择题