胎头于宫缩时暴露于 * * 口，间歇时又回缩
A．内出血B．外出血C．腹腔出血D．颅内出血E．血尿
参考答案：D
Experts have been warning___of the health risks caused by passive smoking.
A．at a time
B．at one time
C．for some time
D．for the time
下面几个词中，（）属于注释格双音节词略写法。
A.声音一声
B.韭菜一韭
C.癌症一癌
D.苹果一苹
