题目内容：
共用题干第二篇
Diabetes（糖尿病）and Eye Damage
Over 2 million Canadians have diabetes.It is the leading cause of blindness in North
Americans under 65 years of age.Diabetes is a condition where the body either cannot
produce enough insulin（胰岛素）or cannot respond properly to insulin. Insulin is important
because it moves glucose（葡萄糖）,a simple sugar, into the body's cells from the blood.
The food people eat provides the body with glucose,which is used by the cells as a source
of energy.If insulin isn't available or doesn't work correctly to move glucose from the blood
into the cells,glucose will stay in the blood,leading to high blood sugar levels.
High blood sugar levels damage the blood vessels,including the tiny blood vessels in
the eye．This leads to an eye disease known as diabetic retinopathy（糖尿病型视网膜病）.
The retina（视网膜）is an area at the back of the eye that changes light into nerve signals.
With diabetic retinopathy,some blood vessels in the retina are lost,and some of the other
blood vessels begin to"leak"blood.This causes the retina to swell,and gradually cuts off
its supply of oxygen and nutrients（滋养物）.Eventually , the retina starts to grow new
blood vessels to replace the damaged ones.Unfortunately,these new vessels are not as
strong as the old ones.They are more likely to break,causing bleeding in the eye.
At first,people with diabetic retinopathy will not notice any symptoms.As the disease
gets worse , they may notice blurred（模糊的）vision, black spots or flashing lights. As
time goes on,it can progress to blindness.Everyone with diabetes is at risk for diabetic
retinopathy,and the risk increases the longer you've had diabetes.
Fortunately,you can reduce your risk.If you do not have diabetes,but think you may
be at risk for this condition,visit your doctor to be screened for diabetes.If you do have
diabetes:
Have frequent eye check-ups.
Make sure that you monitor your blood sugar frequently and use your medications as
recommended by your doctor. There is evidence to show that keeping your blood sugar
under tight control can slow down eye damage.
If you have high blood pressure,follow your recommended diet and medications to
keep it under control.If you are not sure whether you have high blood pressure,or whether
your blood pressure is under control,discuss this with your doctor.
With diabetic retinopathy,the damaged blood vessels in the retina
A:are stronger than what they used to be.
B: cannot be properly replaced.
C:are more likely to break than the new ones.
D: may return to normal again.
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