下列哪一心音可作为心室舒张期开始的标志
A．第一心音
B．第二心音
C．第三心音
D．第四心音
E．主动脉，二尖瓣关闭音
参考答案：B
— Is there _____ in today's newspaper?
— Yes. A man entered our teachers' office _____ the window last week. [ ]
A. something new; through
B. anything new; through
C. new anything; through
D. anything new; across
