题目

阅读理解Have you ever lost your car on a parking lot? You don't have a clue where your car is after shopping. Then you start walking around clicking on your car keys so the alarm goes off. It can be annoying, especially on a hot sunny day. No, you needn't install (安装) an expensive GPS system to keep track of your car. That's too expensive. You would need to pay a monthly fee to use it. But is there a way to track your vehicle without spending a fortune? Yes, now there is! A California-based company has created a tiny device that works with your smartphone, which could be exactly what y潜水艇在水面上的排水量是3000t，在水下的排水量是3800t，当潜水艇在水面航行时，水上部分的体积是________ m3；若潜入水中时，应吸入水________ kg．（g=10N/kg）