带蒂皮瓣的断蒂手术一般在第一次手术后多久实施（）
A.7天
B.7～14天
C.14～21天
D.21～30天
E.30～40天
参考答案：C
在报社同国家财政的经济关系分析中，判定一个报社属于补贴型报社的标准是：______小于或等于零。
Which statement is FALSE concerning precautions during fueling operations?（）
A.All engines，motors，fans，etc. should be shut down when fueling
B.All windows，doors，hatches，etc. should be closed
C.A fire extinguisher should be kept nearby
D.Fuel tanks should be topped off with no room for expansion
