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ἐνταῦθα δὴ προσχωρεῖ ὁ πάππος καὶ ....

at that very moment. At what 'very moment'?
When ὁ λύκος ἀσπαίρει καὶ καταπίπτει πρὸς τὴν γῆν.
τί οὖν ὁρᾷ ὁ πάππος; - ὁρᾷ τὸν λύκον.
ποῦ ἐστιν ὁ λύκος; - ἐστίν ἐπὶ τῇ γῇ, κείμενος
κείμενος, κειμένη, κείμενον: lying
We had: ὁρμᾷ ἐπὶ τὸν λύκον accusative for movement against, upon
Now: ἐπὶ τῇ γῇ κείμενος, dative for position where
like: ὁ δοῦλος καθεύδει, ὑπὸ τῷ δένδρῳ κείμενος.
like: ὁ Δικαιόπολις ήσυχάζει, ὑπὸ δένδρῷ καθιζόμενος. (sitting under a tree)
like: ἆρ' οὐχ ὁρᾷς τὴν ὑδρίαν in shattered fragments ἐπὶ τῇ γῇ κειμένην;
(Note that ἐπί is also often used with genitive case forms)
 

θαυμάζει οὖν καὶ ....

τὸ θαῦμα, τοῦ θαύματος, wonder, marvel (declension like τὸ ὄνομα )
θαυμάζω, I admire; I am amazed
ὁ πάππος θαυμάζει, is amazed
like: κάμνει, is sick, is tired. (real verb in Greek, to be + adjective in English)
τί θαυμάζει;
2 possibilities for τί;

1. What does he admire?
   θαυμάζει τὴν τοῦ Φιλίππου ἀνδρεῖαν (courage, bravery)
   θαυμάζει καὶ (also) τὴν τοῦ κυνὸς ἀνδρεῖαν
2. Why is he amazed?
   θαυμάζει διότι (because) ὁ Φίλιππος οὕτως ἀνδρεῖός ἐστι ὥστε τύπτει τῇ μαχαίρᾳ τὸν λύκον καὶ ἀποκτείνει αὐτόν. (kills the wolf)

 

εὖ γε. Well done!

πότε λέγομεν· εὖ γε;
τί θαυμάζεις; (Several answers in English of course would be welcome, to show that you do still find some things marvellous, astonishing, wonderful.
 

σὺ δὲ, ὦ Ἄργε, ἀγαθὸς εἶ κύων.

ἀγαθός, ἀγαθή, ἀγαθόν, good, noble; brave; strong; honest
A woman called Agatha is therefore a Good woman
τί ἐστιν ἀγαθὸς κύων ὁ Ἄργος;
εὖ φυλάττει τὴν τε οἰκίαν καὶ τὰ πρόβατα
καὶ (also) βοηθεῖ (helps) τῷ Φιλίππῳ ἐπεὶ δὲ διώκει τὸν λύκον
καὶ (also) βοηθεῖ (helps) τῷ Φιλίππῳἐπεὶ δε λίθοις βάλλει αὐτόν
καὶ (also) βοηθεῖ (helps) τῷ Φιλίππῳἐπεὶ δε τύπτει τὸν λύκον τῇ μαχαίρᾳ
πῶς βοηθεῖ τῷ Φιλίππω; - κατέχει τὸν λύκον.
πῶς κατέχει τὸν λύκον; - λαμβάνει αὐτὸν ὄδαξ.
 

νῦν δὲ, ὦ Φίλιππε,....

(διὰ) τί λέγει οὕτως ὁ πάππος;
He supposes that ἡ δὲ μήτηρ ἐθέλει γιγνώσκειν τί πάσχει ὁ παῖς.
δήπου, adverb meaning: I suppose, supposedly
σὺ δὲ, δήπου νῦν μάλα κάμνεις, or don't you?
δήπου ἐθέλεις ἡσυχάζειν
ἆρα ἐθέλεις ἡσυχάζειν ἐπὶ τῇ γῇ κείμενον; (κειμένη; if you are a woman) ἢ ἄλλως: (or some other way?)

at that very moment: ἐνταῦθα δὴ
I am amazed; I wonder at, I admire: θαυμάζω
up onto; against, at: ἐπί + accusative, ὁρμᾷ ἐπὶ τὸν λύκον
upon, on (position): ἐπί + dative (or genitive), ἐπὶ τῇ κλίνῃ κείμενος (ἡ κλίνη, the bed is where we recline to rest or sleep)
now: νῦν
lying: κείμενος, κειμένη, κείμενον
well done!: εὖ γε
I suppose: δήπου