执行价格的选择要看投资者对后市的判断，以及他对（）的运用。
A.实值期权
B.虚值期权
C.平值期权
D.时间价值
参考答案：A, B, C
In English class, our teacher often creates an environment _____ we are given the opportunity to solve problems ourselves.
A．when
B．where
C．which
D．that
供气消防车可以安全快速给（）只空气瓶进行补气。
A.10.0
B.12.0
C.14.0
D.16.0
