452+393=?,253+446=?,987+706=?
784-47=?,984-660=?,1325-707=?
81+?=840,219+?=759,1244+?=1635
84*7=?,9*19=?,839*4=?
474/3=?,472/8=?,846/6=?
---
?-224=889-441,104+113+424+356=?
741-241=?+393,585+573+348-1287=?
263+?+339=983,1003+588-773-690=?
211+?-540=445,1926-628-551-487=?
喉咙里有痰