既想留着蛋糕,又想吃(既要鱼,又要熊掌)的英文

have one's cake and eat it too

• 既:    already
• 想:    think; ponder
• 留:    remain; stay
• 着:    wear; dress
• 蛋糕:    cake
• 吃:    eat; take; make
• 鱼:    fish
• 熊掌:    bear's paw