Just as an addition, you have not copied the key's lines correctly.
Here's the English text:
It is now midday, and the sun is very hot, The shade of the trees is cool, and the lake is beautiful.
I see many swans, which are bright and white. The neck of that swan is long, but the left wing seems
to be small. I do not know the cause of this. Perhaps there is a bad disease in this wing. Perhaps a
bone of this swan was broken by a stone. There is a small boat on* the lake.
* From the vocabulary. on
, ἐπί, g. or d.
Here's the key's Greek rendition:
μεσημβρία νῦν ἐστί *, καὶ ὁ ἣλιος σφόδρα θερμός ἐστιν. ἡ σκιὰ τῶν δένδρων ψυχρά ἐστι, καί ἡ λίμνη καλή.*
ὁρῶ πολλοὺς κύκνους, οἳ λαμπροί εἰσι καί λευκοί. ὁ τράχηλος ἐκείνου τοῦ κύκνου μακρός ἐστιν,
ἀλλὰ τὸ πτερὸν τὸ ἀριστερὸν * δοκεῖ μικρόν εἶναι.* οὐκ οἶδα τήν αἰτίαν τούτου. ἴσως κακή ἐστι * νόσος
ἐν τούτῳ τῷ πτερῷ. ἴσως τούτου τoῦ κύκνου ὀστοῦν * λίθῳ διερράγη. ἐπὶ τῆς λίμνης ἐστὶ μικρὸν πλοῖον.
* I think it should be νῦν ἐστι, as modus said.
* I'm not sure but I think the second ἐστί(ν) was omitted not because it's common in this type of sentence (it is the first
exercise after all) but to show that it's not common to find the same verb repeated in the same sentence. The order here could
have been just as well καλὴ ἡ λίμνη, but maybe it's a parallel order to the first clause.
* τὸ ἀριστερὸν πτερὸν is just as acceptable with the same meaning.
* There's very little experience under my belt, but I've seen similar examples of both δοκεῖ μικρὸν εἶναι and δοκεῖ εἶναι μικρόν.
Best to go with what the key has for now.
* In p.66 of the book, there doesn't seem to be any difference between he/she/it is
and there is
they are both written in the same line of ἐστί(ν). I think it's important to know, as modus noted, that the existential copula, there is
, often appears at the beginning of a clause/sentence and is accented ἔστι(ν), though I don't think this means
that if it appears in other part of the sentence, (and thus accented as 'regular' copula,) it cannot have that meaning.
* The book follows the Attic dialect, which contracts (τὸ) ὀστέον to ὀστοῦν.