1. [ao;wa] mian   segment   concave   polygon   parallelogram   Hint Half-n-half Clue   2. tu mian   convex   quadrilateral   hexagon   prism   Half-n-half Clue   3. jin zi [da;ta]   oval   vertex   ellipse   pyramid   Half-n-half Clue   4. wu [bian;bian] xing   plane   pentagon   prism   polygon   Half-n-half Clue   5. si [bian;bian] xing   parallel lines   perpendicular lines   quadrangle   plane   Half-n-half Clue   6. [bian;bian] yuan   heptagon   ray   oval   edge   Half-n-half Clue   7. ping [hang;hang;heng;xing] [de;di;di] xian   oval   rhombus   straight line   parallel lines   Half-n-half Clue