单选题

　　[完成句子]Lack of sleep can affect everything from our emotions to how well we focus on tasks like driving. It can affect sports performance， increase our chances of getting sick， and may be linked to weight gain in some people. You‘ve probably noticed how much running around little kids do — and how soundly they sleep. Take a tip from a toddler and get at least 60 minutes of exercise a day. Physical activity can decrease stress and help people feel more relaxed. Just don’t work out too close to bedtime because exercise can wake you up before it slows you down.

　　Lack of sleep can increase our chances of ___________.

　　A、feel more relaxed

　　B、waking up in middle night

　　C、getting sick

　　D、Watch TV and surf online