题目

I am a time traveller. At the moment, I 71 _____ (talk) to you from the Dark Ages, where science and technology has been forgotten.    Two months ago, my computer broke and the man in the repair shop said it would be 72_______ (expensive) to fix my computer than to buy a new one！Now, I admit that I am addicted 73_______ the Internet.I spend hours of my free time 74_________  (watch) funny videos on YouTube,scrolling(滚动) through Twitter and playing video games with my friends online. So when I 75________ (inform) that my computer couldn’t be fixed, I was sad！    I have bee当x=（    ）时，二次函数y=x2+2x﹣2有最小值．