建设单位有( )行为，责令改正，处工程合同价款2%以上4%以下的罚款，造成损失的，依法承担赔偿责任。

A．未按照国家规定办理工程质量监督手续的

B．验收不合格，擅自交付使用的

C．以欺骗手段取得资质证书承揽工程的

D．设计单位未根据勘察成果文件进行工程设计的

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.
Spread spectrum simply means that data is sent in small pieces over a number of the (16) frequencies available for use at any time in the specified range. Devices using (17) spread spectrum(DSSS) communicate by (18) each byte of data into several parts and sending them concurrently on different (19) . DSSS uses a lot of the available (20) , about 22 megahertz(MHz).

A．splitting

B．combining

C．packing

D．compacting