。
You must not skim-read.
Literal
Skim-reading [object-を] do [must not-てはいけません].
飛ばし読み means 'skimming' — 飛ばす ('to skip') + 読み ('reading'), a compound noun. ~てはいけません is the polite prohibition meaning 'must not do X.'
。
You must not skim-read.
You must not skim-read.