《中华人民共和国环境噪声污染防治法》规定：在城市市区范围内，建筑施工过程中使用机械设

王某明知某电器产品不符合保障人身安全的国家标准，仍然大量进货销售，销售金额达80万元。某企业因使用这种电器造成短路，引起火灾，致3人轻伤，部分厂房被烧毁。下列说法中正确的是

A．王某的行为己构成失火罪

B．王某的行为已构成销售伪劣产品罪

C．对王某应按照失火罪和销售伪劣产品罪中的一个重罪定罪处罚

D．对王某应按照销售伪劣产品罪和过失伤人罪，数罪并罚

小明和小华一起在探究《平抛物体的运动的规律》的实验中，他们得到了小球做平抛运动的闪光照片，但由于不小心给撕掉了一段，他们在剩下的坐标纸上描出了几个点，如图所示，已知图中每个小方格的边长都是5cm，根据剩下的这块坐标纸求闪光周期为______s

平抛初速度为______m/s，A点的速度为______m/s．

（g取10m/s²，结果保留2位有效数字）

急性阑尾炎继发局限性腹膜炎的处理方法中下列哪一项不正确（）

A.应早期手术

B.术中尽量吸净腹腔内液体

C.用甲硝唑冲洗病灶

D.盲肠缝合不牢固时，可放置引流

E.引流管放置7～10天

This is a famous street in China. What is it It’s West Street. Why is it so famous Now let me tell you something (41) it.
West Street is in Yangshuo, Guangxi. It’s over 1,400 years (42) .It’s about 1,000 meters (43) . But it’s very clean and beautiful. In the street, there are (44) shops. The things in the shops are nice and cheap. Every day, lots of visitors come here. Many of (45) are foreigners. It’s a good place to practice speaking English. So West Street is called the biggest English corner. Some people (46) call it the earth village. Almost everyone in the street (47) English.
But you mustn’t ride your bike or drive your car in the West Street. You can only (48) here. Why Because it’s a walking street. In the street, you needn’t worry that you’ll be hit by cars. (49) happy!
West Street is a wonderful place to visit. (50) West Street.

[A] say [B] says [C] speaks

脉冲编码调制分（）、（）、（）三个步骤。