离心球墨铸铁管浇注时，铁水经扇形包、（）、直流槽进入管模内。
A.球化包
B.中间包
C.斜流槽
D.电炉
参考答案：C
The engine of the ship was out of order and the coming typhoon ________ the helplessness of the crew at sea.
A．added to
B．resulted from
C．turned out
D．made up
轻度缺氧时神经系统的症状主要是
A．昏睡
B．谵妄
C．注意力不集中，智力减退，定向障碍
D．昏迷
E．烦躁不安，神志恍惚
