烧结原料纯度的高低取决于（）的多少。
参考答案：脉石含量和有害杂质含量
已知等腰三角形的一边等于5，另一边等于6，则它的周长等于 _________ ．
Which of the following would be most important to teach a client older than 65 years to prevent a recurrence of bacterial pneumonia（）
A. Change current diet habits.
B. Seek prompt antibiotic therapy for viral infections.
C. Receive prophylactic antibiotic therapy.
D. Obtain annual influenza and pneumococcal vaccines.
