Today was Emily's birthday. She was happy and went home quickly after school.

    “You have to look for your gift on your own，” her sister said. “Here is the first clue(线索).” She gave Emily a piece of paper.

    Emily opened the note and read， “Clue Number 1： Look inside the car.” She found a bone(骨头) for dogs and another note in the car.

    “Clue Number 2： Look at the swing.” On the swing there was a bag of dog food with the third note.

    Again she quickly read the note， “Clue Number 3： Look into the house.” Emily found a dog's leash(皮带) there.

    The note on the leash asked her to go outside. There she saw a beautiful red doghouse.

    Before she got there， a black puppy ran up to her. It had a note on it. The note said， “Happy Birthday， Emily.”

    “Oh， such a cute dog!” she cried. She was so happy. “I will name her Happy， because she made me so happy today，” Emily said.

如图，市煤气公司计划在地下修建一个容积为10⁴m³的圆柱形煤气储存室，则储存室的底面积S（单位：m²）与其深度d（单位：m）的函数图象大致是（　　）

春节放假期间，全国高速公路免费通行，小轿车可以不停车通过收费站，但要求小轿车通过收费站窗口前x₀=9m区间的速度不超过v₀=6m/s．现有甲、乙两小轿车在收费站前平直公路上分别以v_甲=20m/s和v_乙=34m/s的速度匀速行驶，甲车在前，乙车在后．甲车司机发现正前方收费站，开始以大小为a_甲=2m/s²的加速度匀减速刹车．