Only in Zoo's.
The only concrete noun in your sentence is sentence. Note: The noun 'sentence' is a concrete noun only for a written or spoken sentence; the noun 'sentence' as a word for a penalty imposed for a crime conviction is an abstract noun.
Yes, the sentence "your retina is healthy" is correct.
The first noun in a sentence may be the subject of the sentence, but NOT ALWAYS, for example:John sat on the bench. (the noun 'John' is the subject of the sentence)He sat on the bench. (the pronoun 'he' is the subject of the sentence, the first noun in the sentence is 'bench', the object of the preposition 'on')
Which sentence sounds the strongest?
The cheetah stalked its prey, hidden in the undergrowth.
Ferociously, I attacked the jungle's dense undergrowth with a machete.
I can give you several sentences.The men fought their way through the undergrowth.The undergrowth choked the life out of the saplings before they could grow.I hid from the bear by ducking beneath the undergrowth.
The duration of Life in the Undergrowth is 3000.0 seconds.
undergrowth is a bush so it doesn't really have an antonym
Life in the Undergrowth was created on 2005-11-23.
Life in the Undergrowth ended on 2005-12-21.
As evening fell the badgers left their set in the spinney to forage in the fields below. ( a Spinney is small clump of trees with undergrowth)
I heard the rustle of the leaves in the wind. She said she would rustle up some grub. The animal caused a rustle in the undergrowth.
Life in the Undergrowth - 2005 is rated/received certificates of: Australia:G
The sun's rays struggled to penetrate the dense thicket of branches and undergrowth in the forest.
On the forest floor. The densest area is the canopy, but i wouldn't consider it undergrowth.