根据下面资料，回答题
Just when you had figured out how to manage fat in your diet, researchers are now warning against another common mealtime pitfall (陷阱)--salt.
A study by researchers at the University of California, San Francisco ( UCSF), Stanford Uni-versity and Columbia University shows that even a（ 46）decrease in daily salt intake (摄入) can lead to dramatic health benefits. The authors（47）an annual drop of as many as 120,000 cases of heart disease,66,000（48）of stroke and 99,000 heart attacks（49）by high blood pressure after a 3-g-per-day reduction in salt.
The advantages, not surprisingly, were greater for African Americans, who are more likely to（ 50）high blood pressure than other ethnic groups, and for the elderly, since blood vessels stiffen with age, which can lead to higher blood pressure.
"Everyone in the U.S. is consuming salt far in（51）of what is good for them," says lead author Dr. Kirsten Bibbins Domingo of UCSF. "What we are suggesting is that a population wide effort to reduce salt intake, even（52）, will have health benefits."
The team conducted a computer-based analysis to determine the（ 53）of a 3-g-per-day reduction in salt intake on rates of heart disease and death. They also calculated the cost savings emerging from the amount of disease that would be（54）because of lower blood pressure.
The conclusion: by cutting salt intake nationwide, the U. S. could save $10 billion to $ 24 billion（55）in health care costs.
A．accidents
B．annually
C．avoided
D．caused
E．considerable
F．develop
G．documented
H．dramatically
I．excess
J．impact
K．instances
L．modest
M．revised
N．slightly
O．Undertake
第（46）题选