2017
年12月英语四级仔细阅读满分练习题
　　There
isevidence
that
theusual
variety
ofhigh
blood
pressure
is,inpart,
afamilial
disease.
Since
families
have
similar
genes
aswell
assimilar
environments,
familial
diseases
could
beduetoshared
genetic
influences,
toshared
environmental
factors,
ortoboth.
Forsome
years,
therole
ofone　　environment
factor
commonly
shared
byfamilies,
namely
dietary
salt
(i.e.,
sodium
chloride),
hasbeen
studied
atBrookhaven
National
Laboratory.
These
studies
suggest
that
long
excess
salt
in ...