怎样简便就怎样算。（1）45×97+45×3（2）483-154-46（3）68

化学与生活密切相关。

（1）日常生活中食用的鸡蛋、脱脂奶中富含的营养素是_____。

（2）下列物品所使用的主要材料属于天然纤维的是_____（填序号，下同）。

（3）洗涤剂可清洗餐具上的油污，这是因为洗涤剂具有_____功能。

（4）下列做法应该提倡的是_____。

A．垃圾分类

B．减少使用一次性餐具

C．使用可降解的塑料袋

D．淘米水浇花（5）天然气（主要成分为甲烷）是家用燃料。甲烷在空气中燃烧的化学方程式为_____。

根据下表数据分析，与煤（按C计）相比，用天然气做燃料的优点是_____。

若缓解电空阀因故障不能动作，则电空控制器在“运转”位时无法给列车补风。

记入产品成本的职工薪酬是（ ）。

A．车间管理人员的工资

B．在建工程人员的工资

C．专设销售机构人员的工资

D．企业管理部门人员的工资

Open   adj．, verb, nounadj．NOT CLOSED1 allowing things or people to go through: A wasp flew in the open window． She had left the door wide open．

2 （of sb’s eyes, mouth, etc．） with eyelids or lips apart: She had difficulty keeping her eyes open （=" because" she was very tired）．He was breathing through his open mouth．3 spread out; with the edges apart: The flowers are all open now．

4 not blocked by anything: The pass is kept open all the year．NOT FASTENED5 not fastened or covered, so that things can easily come out or be put in: The bag burst open and everything fell out．

verbDOOR / WINDOW / LID1 [vn] to move a door, window, lid, etc．so that it is no longer closed: Mr Chen opened the car door for his wife． close2 [v] to move or be moved so that it is no longer closed: The door opened and Alan walked in． The doors of the bus open automatically．closeCONTAINER / PACKAGE3 [vn] to remove the lid, undo the fastening, etc．of a container, etc．in order to see or get what is inside: Shall I open another bottle? She opened her bag and took out her passport．EYES4 [vn, v] if you open your eyes or your eyes open, you move your eyelids upwards so that you can see closeCOMPUTING5 [vn, v] to start a computer program or file so that you can use it on the screenopen doors for sb to provide opportunities for sb to do sth and be successful open your / sb’s eyes （to sth） to realize or make sb realize the truth about sth: Travelling really opens your eyes to other cultures．open your / sb’s mind to sth to become or make sb aware of new ideas or experiences．

open the way for sb/sth （to do sth） to make it possible for sb to do sth or for sth to happen: The agreement could open the way for the country to pay off its debts．—more at heart, heaven open into / onto sth to lead to another room, area or place: This door opens onto the yard． The two rooms open into each other．open out to become bigger or wider: The street opened out into a small square．open out （to sb） to become less shy and more willing to communicate open up1 to talk about what you feel and think: It helps to discuss your problems but I find it hard to open up．2 to begin shooting: Anti-aircraft guns opened up．3 （often used in orders） to open a door, container, etc．: Open up or we’ll break the door down! open up1 to become or make sth possible, available or able to be reached: The new catalogue will open up the market for our products． The railway opened up the east of the country．

2 to begin business for the day; to start a new business: I open up the store for the day at around 8．30． close up3 to start a new business: There’s a new Thai restaurant opening up in town． close down

noun  the open [sing．] OUTDOORS1 outdoors; the countryside: Children need to play out in the open．NOT HIDDEN2 not hidden or secret: Government officials do not want these comments in the open．

1．Which of the following “open” is closest in the meaning with the “open” in the sentence “The book lay open on the table．”

A．She had left the door wide open． 

B．The bag burst open and everything fell out．

C．The flowers are all open now．    

D．He opened the letter and read it．

2．Fill in the blank in the sentence “He’s eager to __________different kinds of music．”

A．open the minds of his audience to         

B．open the eyes of his audience to   

C．open the way for his audience to listen to   

D．open doors for his audience to listen to

3．What does the phrase “ the open” mean in “ When you feel tired after a day’s hard work, you’d better invite some friends to the open to relax yourself．”

A．the gym       B．the cinema      C．the countryside       D．the music room

4．Choose one of the following to complete the sentence, “Exciting possibilities__________for her in the new job”．

A．were opening out        B．were opening into  

C．were opening onto       D．were opening up