Число формул соединений водорода, в который степень окисления этого элемента +1, в следующем списке H2SO3, ВаH2. H2O2, NaH, NH3

My parents are 40 years old. There are 30 classrooms in my school. There are 27 pupils in my class. There are 20 boys in my class. There are 7 girls in my class. There are 30 days in November. There are 31 days in December. I study in school number 23. My friends live in the house number 18.