請依下文回答第 36 題至第 38 題：
The development of seawater agriculture has taken two directions. Some investigators have attempted to breed salt
tolerance into conventional crops, such as barley and wheat. For example, Emanuel Epstein’s research team at the
University of California at Davis showed as early as 1979 that strains of barley propagated for generations in the presence
of low levels of salt could produce small amounts of grain when irrigated by comparatively saltier seawater.
Unfortunately, subsequent efforts to increase the salt tolerance of conventional crops through selective breeding and
genetic engineering─in which genes for salt tolerance were added directly to the plants─have not produced good
candidates for seawater irrigation. The upper salinity limit for the long-term irrigation of even the most salt-tolerant
crops, such as the date palm, is still less than five part per 1,000(ppt)─less than 15 percent of the salt content of seawater.
Normal seawater is 35 ppt salt.
Our approach has been to domesticate wild, salt-tolerant plants, called halophytes, for use as food, forage, and
oilseed crops. We reasoned that changing the basic physiology of a traditional crop plant from salt-sensitive to
salt-tolerant would be difficult and that it might be more feasible to domesticate a wild, salt-tolerant plant. After all, our
modern crops started out as wild plants. Indeed, some halophytes─such as grain from the saltgrass Disticblis Palmeri─
were eaten for generations by native peoples, including the Cocopah, who live where the Colorado River empties into the
Gulf of California.
【題組】38 Where do you think the Cocopah live?
(A)At the origin of the Colorado River
(B)At the mouth of the Colorado River
(C)Along the Colorado River
(D)At the dried part of the Colorado River
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