食管癌癌前病变多指（）。
A.腐蚀性食管灼伤
B.慢性胃炎
C.食管溃疡
D.食管真菌病
E.食管上皮不典型增生
参考答案：E
看图，选择正确的答案将句子补充完整。
1. Look, I have a ____________ .[ ]
A. panda
B. bear
C. bird
2. Look at the ____________ . It's so big. [ ]
A. duck
B. squirrel
C. elephant
3. Please have some ____________ . Thank you.[ ]
A. hamburgers
B. hot dogs
C. chicken
4. There are two ____________. [ ]
A. kites
B. balls
C. balloons
5. Look, this is my ____________ [ ]
A. eye
B. ear
C. nose
叠合梁表面清理干净后，应在混凝土浇筑前（）吸干积水。
A.0.5h
B.1h
C.2h
D.3h
.[ ]
. It's so big. [ ]
. Thank you.[ ]
[ ]
[ ]