A:孟轲/百舸争流疏浚/怙恶不悛晦气/诲人不倦
B:惆怅/风流倜傥咀嚼/咬文嚼字屏风/气息屏窒
C:甫健/辅导功课勒索/悬崖勒马埋怨/埋下伏笔
D:骸骨/言简意赅宁可/宁缺毋滥犄角/掎角之势
求实数a,b的值;
This kind of desk is wood, and it is made Hunan.