安全阀的设计压力应选择被保护系统内最高的设计压力。
参考答案:错
The old man sat in front of the radio every evening, ______ his favorite program.
A.dying to hear
B.was dying to hear
C.dying to have heard
D.is dying for hearing
()是单胃草食物性动物。
A.牛
B.马
C.羊
D.兔