欧洲哪个民族第一个使用印刷机？

计算题：

用重量法测定地下水水样中硫酸根的含量，从试料中沉淀出来的硫酸钡的重量为0.0800g，试料的体积为200m1，试计算该水样中硫酸根的含量。

1829年英国通过了《警察法》，并由罗伯特•皮尔建立了首都伦敦警察厅。 ( )

The history of African—Americans during the past 400 years is traditionally narrated (1) an ongoing struggle against (2) and indifference on the part of the American mainstream, and a struggle (3) as an upward movement is (4) toward ever more justice and opportunity.

Technology in and of (5) is not at fault; it’s much too simple to say that gunpowder or agricultural machinery or fiber optics (6) been the enemy of an (7) group of people. A certain machine is put (8) work in a certain way—the purpose (9) which it was designed. The people who design the machines are not intent on unleashing chaos; they are usually trying to (10) a task more quickly, cleanly, or cheaply, (11) the imperative of innovation and efficiency that has ruled Western civilization (12) the Renaissance.

Mastery of technology is second only (13) money as the true measure of accomplishment in this country, and it is very likely that by (14) this under-representation in the technological realm, and by not questioning and examining the folkways that have (15) it, blacks are allowing. (16) to be kept out of the mainstream once again. This time, however, they will be (17) from the greatest cash engine of the twenty-first century. Inner-city blacks in particular are in danger, and the beautiful suburbs (18) ring the decay of Hartford, shed the past and learn to exist without contemplating or encountering the tragedy of the inner city.

And blacks must change as well. The ways that (19) their ancestors through captivity and coming to freedom have begun to loose their utility. If blacks (20) to survive as full participants in this society, they have to understand what works now.

20（）

A.is

B.were

C.are

D.have

某市检察分院的反贪局侦查员李某，在办理自侦案件的过程中，认为本案中存在专门性问题，需要由本检察院的技术部门进行鉴定。下列什么人员或机构有权决定进行该项鉴定？( )

A．侦查员李某
B．市检察分院反贪局领导
C．市检察分院检察长
D．市检察分院检察委员会