[单选题]
A certain amount of a monatomic gas is mn de: .fvh1n5eoae,u *aintained at constant volume ajxi4m0;; vp4:h cnl8v jrj3i is it is cooled by 50 K. This feat is accomxvmr3 jiij l ;;hp80vcn:4j4i plished by removing 400 J of energy from the gas. How much work is done by the gas?
