车刀角度中，控制刀屑流向的是（）。
A、前角
B、主偏角
C、刃倾角
D、后角
参考答案：C
血源性呼吸困难见于
A．肝硬化腹水B．急性胃穿孔致腹膜炎C．胰腺囊肿D．癌症晚期恶病质E．腹白线疝
Great changes ______ in the small village since the new road was built. [ ]
A. has taken place
B. have taken place
C. have been taken place
D. has been taken place
