对骨肿瘤的诊断、鉴别诊断，最有价值的检查是（）

A.查相关的肿瘤标志物

B.X线片

C.CT或MRI

D.核素骨扫描

E.组织活检、病理检查

Directions: Complete the following passage by filling in each blank with ONLY ONE WORD that best fits

the context.

     Age-related heart problems are usually due to a combination of factors. High cholesterol (胆固醇) is 

1______ big issue, and 2______ that can be controlled. Stay aware of your checks. In addition, blood

pressure should be measured every year starting at age 21, although now, even pediatricians (doctors for

children) have blood pressure guidelines that they can apply 3______ children 4______ simple way to

protect your heart at your age is to quit smoking and avoid breathing 5______ second-hand smoke. The

effect of smoking 6______ your heart can be compared to crushing a cigarette butt out on the lining of

your artery-extremely damaging. Watch your weight, 7______ make changed-if the pounds start to creep

up on you And eat well. Be sure 8______ your diet delivers quality nutrition and a controlled number of

calories.