NSD 2019: Science Characters (Covalent Bond) Posted on April 5, 2019April 10, 2019 by Arundhati Dolas NSD 2019: Science Characters titled Covi Sisters depicting the Covalent Bond. Idea by students of class 9, Aasfa Patel, Pratiksha Mohite, Prachi Khapurkar from Holy Cross Convent High School, Kalyan.
