五.语法填空 (15分)

Backpacking is a popular activity in the United States. Many different companies produce goods and equipment for those___1___ enjoy living for a while in nature. Several companies sell special foods, some of ___2____ have been produced using a method that removes the water. This method is called freez-drying. These meals include different foods such as meat, vegetables and rice or perhaps a ____3____ (mix) of several foods.

Hot water is added to the ___4_____ (dry) materal to replace the missing water. This produces a meal that ____5____ ready to eat. Backpackers use this method to carry food for two reasons. The food is easy to carry because it weighs a lot less ____6____ the water. And food that has been freeze-dried ___7____ (remain ) safe to eat for a long time.

Also, many companies produce special clothing for people who enjoy backpacking. Some companies make strong shoes made for walking and hiking. ____8____ make small stoves for cooking food. Other companies make small lightweight cloth tents campers can carry anywhere

____9______( convenience ). A few companies sell equipment that makes water safe to drink. And ___10______ number of companies make the backpacks that campers use to carry all this equipment.

1. _________  2. ____________  3. ______________  4. ____________  5. __________

6. _________  7. ____________  8. ______________  9. ____________  10.__________

某电气安装工程项目，业主与某电力工程公司签订了工程项目总承包合同。该工程项目的变压器采用自耦式变压器(容量为800kV·A)，电机采用三相异步电动机。
该工程项目的设计单位对变压器的采购编制了采购计划，经业主批准后，由项目经理进行采购。工程监理单位负责对变压器检验的组织工作。变压器运抵施工现场后，进行了开箱验收，经验收合格后，按吊装、吊芯检查、就位、试验、干燥的程序和要求进行安装。变压器安装完毕后，进行了绝缘油的击穿电压试验和交流耐压试验。绝缘油在试验时，温度一直保持在40℃左右，且在清洗注油后即开始加电压试验。变压器安装完成后静止5h开始进行交流耐压试验。
三相异步电动机在检查过程中经电气试验发现质量可凝。
1.变压器按照绕组数目可分为哪几类该变压器是否应做吊芯检查说明理由。