浓缩血小板的保存最佳温度是()A．22～23℃ B．20～22℃ C．20～24℃

A client with diabetes is explaining to the nurse how he cares for his feet at home. The nurse could judge from which of the following statements that the client needs further instruction on how to care for his feet properly

A. "I inspect my feet once a week for cuts and redness. "
B. "I am not allowed to use a heating pad on my feet. "
C. "It is important to dry my feet carefully after my bath. "
D. "I should not go barefoot, even in my home. "

高血压伴心绞痛及哮喘患者，出现肾功能不全时，下列最适合治疗药是（）

A.卡托普利

B.普萘洛尔

C.硝苯地平

D.氢氯噻嗪

E.哌唑嗪

某种疾病在发生和发展过程中，职业因素是其危险因素之一，但不是唯一的直接的病因，个体因素也发挥作用。职业因素可促使潜在的疾病显露或加重已有的疾病的病情。改善工作条件则可使所患疾病得到控制或者缓解。这一类疾病称为（）

A.职业病

B.职业性疾病

C.工作有关疾病

D.工作多发病

E.职业性特征

For ship-to-shore distress alerts, you can use（）.

A.INMARSAT, EPIRB and DSC

B.NAVTEX, NBDP and R/T

C.INMARSAT, VHF and SART

D.EPIRB, DSC and radar

已知A为n阶实对称阵，λ_i(i=1，2，…，n)是A的n个特征值，则实二次f=X^TAX在‖X‖=1时的最大值为______。