化学有害因素的职业接触限值包括时间加权平均容许浓度、()和最高容许浓度三类。
参考答案:短时间接触容许浓度
在图像中分别表示:向一定量的硫酸钠溶液中滴加氯化钡溶液,溶液中有关物质质量的变化,正确的是()。
A.A
B.B
C.C
D.D
In Malsenia sales of classical records are soaring. The buyers responsible for this boom are quite new to classical music and were drawn to it either by classical scores from television commercials or by theme tunes introducing major sports events on television. Audiences at classical concerts, however, are continually shrinking in Malsenia. It can be concluded from this that the new Malsenian Converts to classical music, having initially experienced this music as recorded music, are most comfortable with classical music as recorded music and really have no desire to hear live performances. The argument assumes which one of the following
A.To sell well in Malsenia, a classical record must include at least one piece familiar from television.
B.At least some of the new Malsenian buyers of classical records have available to them the coupon of attending classical concerts.
C.The number of classical concerts performed in Malsenia has not decreased in response to smaller audiences.
D.The classical records available in Malsenia are for the most part not recordings of actual public concerts.
E.(E) Classical concerts in Malsenia are not limited to music that is really available on recordings.