Working hard but to no avail：劳而无功

相儒以沫 Moistening each other with soliva | 劳而无功 Working hard but to no avail | 视为畏途 Regarded as a dangerous road

arch gravity dam：拱形重力坝

arch dam拱坝 | arch gravity dam拱形重力坝 | arch structure拱形结构

somatome：体节

somatology 躯体学 | somatome 体节 | somatomegaly 巨大症