控制焊缝含氢量，可防止（）。
A、热裂纹
B、冷裂纹
C、变形
参考答案：B
选用过滤器应考虑（）、（）、（）和其它功能，它在系统中可安装在（）、（）、（）和单独的过滤系统中。
A client being evaluated in the emergency department complains of chest pain that radiates to his neck, shoulders, back, and arms, which decreases when he sits up and leans forward. Based on this assessment, the nurse suspects that he has
A．developed another myocardial infarction (MI).
B．endocarditis.
C．pericarditis.
D．myocarditis.
