回天乏術

回 = 口 + 囗 : Helga Horse (hu-) smuggled herself into the Eiffel Tower's kitchen (-ei2). She covered herself in an enclosure (囗) full of mandarins (口). Unfortunately, she missed one little detail: The box full of mandarins is to be shipped back (回) to China soon.

天 = 一 + 大 : Mnemonic symbol: an angel from heaven. Mother Teresa (ti) programmed a robot (大) to play a flute duet together with her in front of the anthill (an1). As they play their flutes (一) an angel (mnemonic symbol for 天) hears their heavenly tune and descends from heaven (天) to listen to them.

乏 = 丿 + 之 : A futon. Frankenstein's monster just entered the ashram and finds a futon. Tired as he his, he immediately goes to bed, covers himself with a big banana peel and makes loud zZz sounds as he sleeps.

术 = 丶 + 木 : Mnemonic symbol from 手术: surgeon

术 = 丶 + 木 : In the space station's bathroom the surgeon wants to tickle Sheldon Shrimp with a petal leaf, but Sheldon thinks it's a trap and he wants to cut him open, so he hides behind a Christmas tree.