循环冷却水系统中金属设备的腐蚀易产生的问题有()。
A、热交换器泄漏
B、材质强度下降
C、热交换器换热效率下降
D、泵压上升
参考答案:A,B,C
确诊主动脉夹层最可靠、安全的首选方法是()
A.心电图
B.DSA
C.选择性动脉造影
D.经胸超声心动图
E.MRI或CT
One may find more ______ in Chinese than in English in descriptive writing.
A. adjectives and metaphors B. pronouns and adjectivesC. hyperboles and pronouns D. nouns and pronouns