国开题库

国开题库

The manager asked me I could finish my work before the weekend.

#A.what#B.whether#C.which
查看详情 +
SQL标准中事务的四种隔离级，MySQL数据库的InnoDB存储引擎中默认采用的是（）。

#A.未提交读（Read Uncommitted）#B.提交读（Read Committed）#C.可重复读（Repeatable Read）#D.可串行化（Serializable）
查看详情 +
The majority of these team challenges ______ anywhere.

#A.can deliver#B.are delivered#C.can be delivered
查看详情 +
SQL Server 2008最核心的服务是SSMS。（）

#A.对#B.错
查看详情 +
The main reason of building a space elevator instead of using rockets is that .

#A.the technology needed in building a space elevator is easier than that of rockets#B.the safety of a space elevator is better than that of rockets#C.the cost of building a space elevator is a fraction of using rockets
查看详情 +
SPWM就硬件方面讲，产生SPWM控制信号的方法主要有：（）。

#A.采用微处理器#B.采用专用大规模集成电路#C.采用微处理器和专用大规模集成电路相结合#D.采用分立元件组成
查看详情 +
The machine _____this morning for no reason.

#A.broke off#B.broke down#C.broke up
查看详情 +
SPWM的输出脉冲电压加到电机上，所得到的电流波形接近于正弦波。

#A.对#B.错
查看详情 +
The longest rail link is _____.

#A.from Moscow to Beijing.#B.from Zhejiang of China to Spain.#C.He is an architect.
查看详情 +
SPWM的基本思想是保持输出脉冲电压幅度不变，用调节脉冲的宽度和间隔实现其平均值接近正弦（同时改变U和f）。

#A.对#B.错
查看详情 +

TOP