18.
如图,直线a∥b,直线c与直线a,b相交,若∠1=56°,则∠2等于( )
| A. | 24° | B. | 34° | C. | 56° | D. | 124° |
10.函数y=$\frac{\sqrt{x-1}}{x-2}$中,自变量x的取值范围是( )
| A. | x≥1 | B. | x>1 | C. | x≥1且x≠2 | D. | x≠2 |
9.等腰三角形的两边长分别为4cm和8cm,则它的周长为( )
0 283944 283952 283958 283962 283968 283970 283974 283980 283982 283988 283994 283998 284000 284004 284010 284012 284018 284022 284024 284028 284030 284034 284036 284038 284039 284040 284042 284043 284044 284046 284048 284052 284054 284058 284060 284064 284070 284072 284078 284082 284084 284088 284094 284100 284102 284108 284112 284114 284120 284124 284130 284138 366461
| A. | 16cm | B. | 17cm | C. | 20cm | D. | 16cm或20cm |