关于标准差,表述正确的是() A.标准差的单位与原始数据的单位不相同 B.标准差的单

题型:单项选择题

问题:

关于标准差,表述正确的是()

A.标准差的单位与原始数据的单位不相同

B.标准差的单位与原始数据的单位相同

C.同一资料的标准差一定比例数小

D.同一资料的标准差一定比均数大

E.标准差就是标准误

考点:北京住院医师公共卫生学Ⅰ阶段北京住院医师公共卫生学(综合练习)北京住院医师公共卫生学(综合练习)题库
题型:单项选择题

生产性粉尘危害程度级别越高,危害越大。对( )级以上危害级别的作业场所,要求做出改进计划,限期整改,甚至停产。

A.Ⅰ

B.Ⅱ

C.Ⅲ

D.Ⅳ

题型:单项选择题

燃油压力低的因素不包括()。

A、燃油管路内有空气

B、燃油滤清器脏

C、精滤后调压阀故障

D、撒砂阀故障

题型:单项选择题

属于几类洞()

A.Ⅰ类洞

B.Ⅱ类洞

C.Ⅲ类洞

D.Ⅳ类洞

E.Ⅴ类洞

题型:单项选择题

对于细木工板,宜采用()测定游离甲醛的释放量。

A.环境测试舱法

B.穿孔法

C.干燥器法

D.密封法

题型:单项选择题

College sports in the United States are a huge deal. Almost all major American universities have football, baseball, basketball and hockey programs, and (1) millions of dollars each year to sports. Most of them earn millions (2) as well, in television revenues, sponsorships. They also benefit (3) from the added publicity they get via their teams. Big-name universities (4) each other in the most popular sports. Football games at Michigan regularly (5) crowds of over 90, 000. Basketball’s national collegiate championship game is a TV (6) on a par with any other sporting event in the United States, (7) perhaps the Super Bowl itself. At any given time during fall or winter one can (8) one’s TV set and see the top athletic programs--from schools like Michigan, UCLA, Duke and Stanford-- (9) in front of packed houses and national TV audiences.

The athletes themselves are (10) and provided with sch61arships. College coaches identify (11) teenagers and then go into high schools to (12) the country’s best players to attend their universities. There are strict rules about (13) coaches can recruit--no recruiting calls after 9 p. m. , only one official visit to a campus--but they are often bent and sometimes (14) . Top college football programs (15) scholarships to 20 or 30 players each year, and those student-athletes, when they arrive (16) campus, receive free housing, tuition, meals, books, etc.

In return, the players (17) the program in their sport. Football players at top colleges (18) two hours a day, four days a week from January to April. In summer, it’s back to strength and agility training four days a week until mid-August, when camp (19) and preparation for the opening of the September-to-December season begins (20) During the season, practices last two or three hours a day from Tuesday to Friday. Saturday is game day. Mondays are an officially mandated day of rest.

19()

A.recalls

B.enlists

C.convenes

D.collects

更多题库