Can you find a simile in act 3 of Romeo and Juliet?

Here are a couple examples of similes from Act III of Romeo and Juliet.  In the first, Benvolio is explaining to the Prince in scene i how both Mercutio and Tybalt came to be killed.  As Benvolio explains, Romeo first tried to break up the fight between Tybalt and Mercutio, but when Romeo realized that Tybalt had killed Mercutio, he took up his sword:

But by and by comes back to Romeo,
Who had but newly entertain'd revenge,
And to 't they go like lightning, for, ere I
Could draw to part them, was stout Tybalt slain.

Benvolio compares the quickness of their fight's commencement and duration to lightning, which comes suddenly and unexpectedly, and just as quickly is gone.  Before Benvolio could take action to stop the fight, it was over, and Tybalt was dead.

The next simile is seen in Juliet's speech at the beginning of scene ii, as she waits eagerly for Romeo to arrive.  At this point, she has not yet heard the news of Tybalt's and Mercutio's deaths or of Romeo's banishment.  All she can think of is spending the night with Romeo, as she says:

O, I have bought the mansion of a love,
But not possess'd it, and, though I am sold,
Not yet enjoy'd: so tedious is this day
As is the night before some festival
To an impatient child that hath new robes
And may not wear them.

She is looking forward to being able to consummate her love with Romeo, and she compares the long, tedious hours of her waiting for him to the impatient waiting of a child anxious to wear new robes to a festival. 

What phrase in Act 3 of Romeo and Juliet is a simile?

Act Three of Shakespeare's Romeo and Juliet is riddled with similes. One of these similes occurs after the duel between Mercutio, Tybalt, and Romeo, in which Mercutio and Tybalt were both killed. The Prince arrives on the scene after Romeo flees, and Benvolio is left to attempt to verbally clean up the mess that has been made.

Benvolio explains to the Prince that Romeo had tried to end the fight between Tybalt and Mercutio but was unsuccessful in doing so. After Tybalt killed Mercutio, Romeo attacked Tybalt in a rage. Benvolio describes this duel as follows:

But by and by comes back to Romeo,

Who had but newly entertain'd revenge,

And to 't they go like lightening, for, ere I

Could draw to part them, was stout Tybalt slain.

I have placed the simile in bold typeface. Benvolio is figuratively comparing the beginning of Tybalt and Romeo's fighting to lightning in order to articulate how sudden it was. There was literally nothing Benvolio could have done to intervene given how quickly the situation escalated. 

What phrase in Act 3 of Romeo and Juliet is a simile?

Another simile in Act Three, is when Mercutio, Benvolio, Page and the servants enter the public place in the street and Mercutio is fooling around with Benvolio.  Mercutio tells him, "Thy head is as full of quarrels as an egg is full of meat; and yet thy head hath been beaten as addle as an egg for quarreling." Mercutio is teasing Benvolio about his eagerness to fight when Benvolio is not a fighter and very timid. I feel Mercutio is really talking about himself because he can be a hot-head if pushed far enough. 

Source:  The Literature and Language Book by McDougal Littell

What phrase in Act 3 of Romeo and Juliet is a simile?

Here's one, spoken by the Friar,  in 3.3.130-134, in which he compares Romeo's intelligence to a careless solider whose gun powder explodes in his face, because he is either too inexperienced or negligent to treat it properly:

Thy wit, that ornament to shape and love,
Misshapen in the conduct of them both,
Like powder in a skitless soldier's flask,
Is set afire by thine own ignorance,