[答案]
Thesechildrenareinthesciencemuseum.
[解析]
根据所给词汇和标点可知,这是陈述句,主语为These children,be动词是are,后面用介词短语作表语,in the science museum在科学博物馆。句子可以连接为These children are in the science museum.
故答案为:These children are in the science museum.
[点评]
本题考查了"陈述句肯定形式,",属于"常考题",熟悉题型是解题的关键。