The idiom ‘bolt from the blue’ means:
The idiom 'smell a rat' means
He cannot get that contract. It is a wild goose chase. (Meaning close to the idiom underlined)
The idiom ‘ivory tower’ approximately means :
Give the meaning of the following phrase get at.
Replace the word underlined by right phrase given:
Since the weather is bad, we will cancel the meeting arranged for this evening