American cars were not popular in their domestic markets because they were ______.
A. small
B. gas consuming
C. fuel efficient
D. not attractive
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艾森克认为,性格差异除表现为内外倾以外,还有稳定性和()性。
A. 敏捷
B. 直觉
C. 求实
D. 独立
在SQL Server 2000中,有商品表(商品号,商品名,单价)和销售表(商品号,销售时间,销售价格)。现要限制“销售价格”的取值必须在此商品“单价”的0.6倍到1.5倍范围之内,实现这个约束的正确代码是______。
A. CHECK(销售价格BETWEEN单价*0.6 AND单价*1.5)
B. CHECK(销售价格BETWEEN商品表.单价*0.6 AND商品表.单价*1.5)
CREATE TRIGGER tri_Sales ON销售表FOR INSERT,UPDATE AS IF EXISTS(SELECT*FROM INSERTED a JOIN商品表b ON a.商品号=b.商品号 WHERE销售价格NOT BETWEEN单价*0.6 AND单价*1.5) ROLLBACK
D. CREATE TRIGGER tri_Sales ON销售表INSTEAD OF INSERT,UPDATE AS IF EXISTS(SELECT*FROM INSERTED a JOIN商品表b ON a.商品号=b.商品号 WHERE销售价格NOT BETWEEN单价*0.6 AND单价*1.5) ROLLBACK
In the modulation style. of PSK, if a kind of Modem's modulation rate is 3200baud and it's
A. 14.4kbps
B. 28.8kbps
C. 9600bps
D. 3200bps
网络中进行数据交换必须遵守网络协议,一个网络协议主要由三个要素组成C语法、语义和 ()。
A. 时序
B. 软件
C. 原语
D. 数据