How can light, which has no mass, be affected by gravity?
1	How	how	ADV	WRB	PronType=Int	11	advmod	11:advmod	Discourse=joint-list_m:7->6:0
2	can	can	AUX	MD	VerbForm=Fin	11	aux	11:aux	_
3	light	light	NOUN	NN	Number=Sing	11	nsubj:pass	6:nsubj|11:nsubj:pass	Entity=(27-substance-new-cf2-1-sgl|SpaceAfter=No
4	,	,	PUNCT	,	_	6	punct	6:punct	_
5	which	which	PRON	WDT	PronType=Rel	6	nsubj	3:ref	Discourse=elaboration-attribute:8->7:0
6	has	have	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	acl:relcl	3:acl:relcl	_
7	no	no	DET	DT	Polarity=Neg|PronType=Art	8	det	8:det	Entity=(28-abstract-new-cf3-2-sgl
8	mass	mass	NOUN	NN	Number=Sing	6	obj	6:obj	Entity=28)27)|SpaceAfter=No
9	,	,	PUNCT	,	_	3	punct	3:punct	_
10	be	be	AUX	VB	VerbForm=Inf	11	aux:pass	11:aux:pass	Discourse=same-unit_m:9->7:1
11	affected	affect	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	0:root	_
12	by	by	ADP	IN	_	13	case	13:case	_
13	gravity	gravity	NOUN	NN	Number=Sing	11	obl:agent	11:obl:agent	Entity=(2-abstract-giv:inact-cf1-1-coref)|SpaceAfter=No
14	?	?	PUNCT	.	_	11	punct	11:punct	_
