CBSE Board class 10 & 12 results to be out by July 15, re-exam possible if students unhappy with score; Delhi CM Arvind Kejriwal cautioned about a sudden drop in oxygen levels in some Covid patients, asks even asymptomatic cases to monitor oxygen levels at home; CRPF jawan, 5-year-old boy killed in terrorist attack in Bijbehara, J&K; Monsoon covers entire country, heavy rains in Bihar, light rains in Delhi NCR expected and more news