先天性腹股沟斜疝的发病因素主要是
A．
B．腹壁强庋降低
C．腹壁缺损
D．腹膜鞘状突未闭
E．先天性腹横肌和腹内斜肌发育不全
参考答案：D
水域式除尘器的工作原理是什么？
Which of the following is least likely an indicator of impairment（）
A. Large cost overruns.
B. Negative changes in the business climate.
C. The market value of an asset appreciates unexpectedly.
