An 18-month-old child is brought to the emergency department with suspected croup. The child appears frightened and cries as the nurse approaches him. The nurse needs to assess the child’s breath sounds. The best way to approach the child is to（）

A. expose the child’s chest quickly and auscultate breath sounds as quickly and efficiently as possible.
B. ask the mother to wait briefly outside until the assessment is over.
C. tell the child the nurse is going to listen to his chest with the stethoscope.
D. allow the child to handle the stethoscope before listening to his lungs.

下列关于自身抗体的叙述，不正确的是

A．类风湿因子阳性可以见于干燥综合征患者和正常人

B．患者抗JO-1抗体是多发性肌炎的特异性抗体

C．ANCA的抗原是髓过氧化物酶

D．抗RNP抗体可以出现在所有的混合性结缔组织病中

E．抗Sol-70抗体是系统性硬化症的特异性抗体