女性，25岁，心脏超声检查示：二尖瓣开放受限，回声轻度增强，左心室内仅见一组 * * 肌，前后瓣叶的腱索均附着于此，考虑为（）。
A.二尖瓣吊床样改变
B.降落伞样二尖瓣
C.二尖瓣关闭不全
D.二尖瓣发育不良
E.以上都不是
参考答案：B
解析：降落伞样二尖瓣是先天性二尖瓣狭窄的一种，左心室内仅见一个 * * 肌，前后瓣叶的腱索均附着于此。
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| There 1 a shop near my home. The people in the shop are friendly. 2 Saturday afternoons, we often go 3 things there. It opens at nine in the morning and 4 late in the evening. You can buy many things in the shop. You can buy food, clothes, school things and other things. But 5 no English books there. Now we are in the shop. My mother 6 to buy a shirt for my father and a blouse 7 me. Then we'd like to have a drink 8 orange. |
| ( ) 1. A. is ( ) 2. A. On ( ) 3. A. and buy ( ) 4. A. close ( ) 5. A. there is ( ) 6. A. want ( ) 7. A. for ( ) 8. A. of | B. are B. In B. and buying B. closes B. there are B. wants B. of B. for | C. am C. At C. and buys C. closed C. has C. wanting C. to C. on | D. does D. Of D. and bought D. closing D. is D. wanted D. on D. to |