题目

某二元酸H2A的电离情况为：H2A=H++HA-；HA- H++A2-。请据此回答下列有关问题： 1）Na2A溶液呈       （填“弱酸性”、“中性”或“弱碱性”），其理由是      （用离子方程式表示）。 2）写出NaHA溶液中溶质电离常数（Ka）的表达式           。 3）如果25℃时，0.10 mol·L-1 H2A溶液的pH=-lg0.11，则0.10 mol·L-1的H2A溶液中c(A2-)=        mol·L-1。【江苏省淮安市2015年中考英语试题】任务型阅读（共10小题；每小题2分，满分20分）BMany companies today hold meetings to discuss their new plans. As people are paying more attention to the environment problems, more companies are looking for ways to reduce their bad influence on the environment. Many of them achieve this by using web meeting.Web meeting is a technology that allows people to communicate better over the Internet. It’s an easy way of hosting and attending a meeting. Participants(与会者) don’t have to leave the office. Each of them will receive an invitation with the meeting time and date on it. When the meeting is ready to begin, they must sit before their computers.With web meeting, all participants can attend the meeting at their own desks. They don’t need to drive a car to travel to and from the meeting. As a result, no fuel（燃料) is used and less time is taken up in attending a web meeting.Materials for the meeting are simply e-mailed to all the participants before it begins. Then participants can just read them on the screen. For the company, this not only saves the use of paper but also greatly reduces the mailing cost.As a meeting hall is not used, the only power for a web meeting is the power that is used by the computers. Besides, organized don’t have to pay for food or accommodation（住宿)for the participants. All this means that less energy is used.In a word, web meeting is a cheaper, greener, and more friendly way of hosting and attending a meeting. Companies that hold web meetings are willing to work hard for a better environment. So they can more easily find their working partners who have the same green ideas. In return, they develop good relationship with other companies and improve their business.根据上面短文内容填空。【1】Many companies are looking for ways to _________ on the environment, because people are paying more attention to the ________.【2】Web meeting is an easy way to _________the meeting. Participants just sit before their computers instead of ________________the office.【3】The use of paper___________and the __________is greatly reduced by e-mailing meeting materials.【4】Power is only used by the computers because there is no need for a__________. Besides, organizers needn’t ________on food and accommodation for the participants.【5】If they have the same___________, it’s ________for companies to find their working partners.