题目

 Zuhur Yasin has never been to the US, but she holds a bachelor’s degree from an American university. Part of Yasin’s studies in Somaliland were spent in a special classroom, lined with rows of computers equipped with webcams（网络摄像头）and microphones. The 29-year-old watched videos and took part in live virtual(虚拟的) classes at Indiana University as part of her journalism programme at the University of Hargeisa.“We had discussions and shared any challenges or questions,” she says. The African Virtual University(AVU), an intergovernmental organization, connected 如果用两种不同方法分别切断同一碱基序列的脱氧核苷酸链，得到两组片段是则比较两组片段的碱基序列，推断原脱氧核苷酸的全部碱基序列应该是A．③②①④B．①④③②C．②①④③D．④②③①