Yuan Longping，one of （最伟大的科学家），made important contributions to the world.
Mike often （收集）stamps and plays basketball in his spare time.
The big tree over there is probably one （百）years old.
It's not safe to leave a baby in a car by （它自己）.
假设你对Henry组织的夏令营感兴趣，请在Camp X﹣treme 的网页上留言，向Henry 询问今年夏令营的相关信息（如举办时间、地点或活动内容等）。请咨询一个问题，完成下面小题。
Henry，I'd like to enter your Camp X﹣treme. （不超过10个单词）
遇到麻烦时,艾伦经常请求帮助。
Alan often help when he is in trouble.