. "down"@en-us . . "i+s"^^ . "301696049"@en-us . . "down pat"@en-us . "0"^^ . . . "understood perfectly; \"had his algebra problems down\""@en-us . . "i+s"^^ . . "down"^^ . "301750617"@en-us . "301750617"^^ . "0.5"^^ . . "mastered"@en-us . . "01750617-a"^^ . "301687446"@en-us .