If you need to call your parents but your phone is not with you, can you remember their numbers? To remember 11 numbers is not difficult. However, because of the smartphone, many of us are losing this ability. What's more, smartphones weaken our skills at giving directions, as well as killing face-to-face communications. Even when friends are having a meal together, it's common for most to check their phones. According to a report by Kleiner Perkins Caufield Byers, an American company, Chinese people spend about 170 minutes on their smartphones daily. Many students are _ to using smartphones. It does no good to their study. Research by Japan's Education Ministry showed children who spend more than four hours a day on their phones perform much worse in school test than those who play with their phones for 30 minutes. It's true that the smartphone has made our lives easier. But many also think they spend too much time on it, and this is bad for their study or work. People are trying to change that. A new app called Forest was introduced this month. It lets users plant a seed that grows into a tree over the next 30 minutes. During the half hour, users cannot use their phones, or the tree will die. A restaurant in Los Angeles, US, gives people a 5% discount   if they don't check their phones during a meal. Owner Mark Gold said he hopes it gives people a way to enjoy their meal and actually talk with friends and family in person. By giving people a 5% discount, Owner Mark Gold wants his customers to   _  .
enjoy a cheaper meal say no to smartphones check phones after the meal improve face-to-face communication