一望而知

to be evident at a glance (idiom)

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

full moon / to hope / to expect / to visit / to gaze (into the distance) / to look towards / towards

15th day of month (lunar calendar) / old variant of 望[wang4]

and / as well as / and so / but (not) / yet (not) / (indicates causal relation) / (indicates change of state) / (indicates contrast)

to know / to be aware