Call me at 5: 30 tomorrow morning—Why that early I _____ then

How _______ it is to feel the roller coaster _______ at full speed!

The sign ______ ,“No parking.”

下列各句中，所引诗词最符合语境的一项是（ ）

Not until all the fish died in the river _____ how serious the problem of water pollution was. [ ]