题目

Life in the 22nd century will be different from life in the 21st century, because many changes will take place in the new century. But what will the changes be? The population is ______ fast. There will be more and more people in the world and most of them will live ______ than before. ______ will be much smaller and more useful, and there will be at least one in every home. And computer studies will be one of the important subjects at ______ . People will work fewer hours than they did in the 21st century, and they will have more free time for sports， ______ TV and traveling. Traveling will18．已知函数f（x）=（x+a）ex（x＞-3），其中a∈R．（1）若曲线y=f（x）在点A（0，a）处的切线l与直线y=|2a-2|x平行，求l的方程；（2）讨论函数y=f（x）．