14.从下列四张卡片中任取一张,卡片上的图形既是轴对称又是中心对称图形的概率是( )

| A. | $\frac{1}{4}$ | B. | $\frac{1}{2}$ | C. | $\frac{3}{4}$ | D. | 1 |
11.若(x-2)(x+3)=x2+ax+b,则a,b的值分别为( )
0 291936 291944 291950 291954 291960 291962 291966 291972 291974 291980 291986 291990 291992 291996 292002 292004 292010 292014 292016 292020 292022 292026 292028 292030 292031 292032 292034 292035 292036 292038 292040 292044 292046 292050 292052 292056 292062 292064 292070 292074 292076 292080 292086 292092 292094 292100 292104 292106 292112 292116 292122 292130 366461
| A. | a=5,b=-6 | B. | a=5,b=6 | C. | a=1,b=6 | D. | a=1,b=-6 |