雪深是从积雪表面到（）的垂直深度，以厘米为单位，取整数。

A 6-year-old girl has been hospitalized with rheumatic fever for 4 weeks. Her symptoms have gradually subsided, and she’s now ready for discharge. Which of the following plans for her health care is most important for her future well-being

A. Arrange for her to return to school as soon as possible to promote psychosocial development.
B. Encourage her to engage in unrestricted physical activity to regain physical strength.
C. Arrange for the administration of prophylactic antibiotics to prevent a recurrence of rheumatic fever.
D. Maintain seizure precautions, as central nervous system involvement may persist for several months.

某商场根据过去的经验，在一年中每增加500万元的销售额，需增加30人，预计一年后销售额将增加1500万元，如果管理人员、销售人员和后勤服务人员的比例是1：6：2，则新增加的人员中，管理人员应为（）人。

A.10

B.20

C.50

D.60

林权争议，或称山林权纠纷，有广义与狭义之分，请问林木、地的所有权和使用权发生争议，属何种意义上的争议（）

A、广义

B、狭义

某物质A的分解反应为一级反应，其起始浓度c_A,O=0.1mol·dm^-3，经50min后分解了c_A,O的20%，则反应的速率常数k=( )min^-1。若c_A,O=0.2mol·dm^-3，同样分解c_A,O的20%所需时间t=( )min。

A．(4.46×10^-3,50

B．(3.22×10^-2,6.93

C．(4.46×10^-3,360.86

D．(3.22×10^-2,50

人类体细胞具有多少对常染色体（）

A.1

B.22

C.23

D.44

E.46