题目

       阅读下面短文，掌握其大意，然后从1~15各题所给的A、B、C和D项中，选出最佳选项，并在答题卡上将该项涂黑。 In my double profession as an educator and health care provider, I have worked with numerous children infected with the virus that causes AIDS．The relationships that I have had with these special kids have been gifts in my life．They have taught me so many things, but I have especially learned that great    1    can be found in a weak small body．Let me tell you about Tyler． Tyler was     2     infected with H关于重力加速度，下面说法正确的是（ ）A. 轻、重物体重力加速度不同B. 重力加速度表示自由下落物体运动的快慢C. 重力加速度表示自由下落物体运动的速度变化的大小D. 重力加速度表示自由下落物体运动的速度变化的快慢