螺钉

螺 = 累 + 虫 : Lenny Lemur (lu) is trying to catch a mosquito (虫) in the observatory's kitchen (o2). To this end he attached a conch (螺) to the end of a rope (累) and throws the conch at the mosquito, hoping to catch it inside. After a miss he can just retract the conch with the rope.

钉 = 丁 + 钅 : Dorothy Gale (di) is eating a quarter of a pizza (丁) in front of the engine ((e)ng1) with a golden harpoon (钅) when she suddenly finds a nail (钉) on the pizza.

钉 = 丁 + 钅 : Dorothy Gale (di) uses the nail (钉) she found earlier to nail (钉) her pizza (丁) to the wall of the engine's bathroom ((e)ng4) to serve as warning for other visitors. As a hammer she uses a golden harpoon (钅).