idiom · a complicated, difficult, or tricky job or metaphorical path that is hard to navigate

这种复杂的科研工作就像是在走羊肠小道。

idiom · a road as twisty as a sheep's intestine; a narrow and winding path, especially in the mountains

穿过这片丛林，只有一条崎岖的羊肠小道。