"There are several possible explanations for this.
1	"	"	PUNCT	FB	_	3	punct	_	SpaceAfter=No
2	There	there	PRON	_	_	3	expl	_	_
3	are	be	VERB	V	Mood=Ind|Number=Plur|Tense=Pres|VerbForm=Fin	0	root	_	_
4	several	several	ADJ	A	Degree=Pos	6	amod	_	_
5	possible	possible	ADJ	A	Degree=Pos	6	amod	_	_
6	explanations	explanation	NOUN	S	Number=Plur	3	nsubj	_	_
7	for	for	ADP	E	_	8	case	_	_
8	this	this	PRON	PD	Number=Sing|PronType=Dem	6	nmod	_	SpaceAfter=No
9	.	.	PUNCT	FS	_	3	punct	_	_
