21.细节理解题Payment,根据文中的 is(到期的)in full upon registration. Registration is required at least two weeks in advance知,要想在博物馆举办生日聚会需要提前至少两周进行预约登记。22.B细节理解Scene-Stealers题。根据-中的 The Director will help you warm up with some theatre games, and teach you some stage skills to get you ready for the audicnce!可知,该活动可以帮助核子们学习一些舞台技巧。23.细节理解题根据 Party中的Cost:s100 for up to10 kids and2 adultssfo each extra child.可知,在DIY活动中如果超出10个孩子就要在支付100美元费用的基础上再为额外的孩子支付每人8美元的费用,即$100+$8x2=116