请根据上下文内容，将文中划线部分译成汉语或者英语。
The police have stepped up their search for a fifteen-year-old boy named Justin Foster. 小题1:He has gone missing since last Friday night. His parents were worried when he didn’t show up for lunch. So they called the police for help.
小题2:人们对他的消失持不同的意见。Kelly, Justin’s younger sister, did see him return home. 小题3:她听到他播放了他最喜欢的CD。But then she saw a large spaceship flying outside and afterwards she heard Justin shout. 小题4:She thought his brother must have been taken away by aliens. According to Mavis Wood, Justin was possibly taken by aliens. She once had the same experience. Luckily she returned home without any injuries.
When asked about the possibility that Justin was taken by aliens, Detective Sam Peterson, who has taken charge of the case, didn’t dismiss it. However, they won’t give up. 小题5:They have been looking into other possibilities as well until they find hard evidence.
