简述路线价法的基本原理。
Good Table Manners
Manners play an important part in making a favorable impression at the dinner table. Here are some general rules： Napkin （餐巾） use
The meal begins when the host unfolds his or her napkin. This is your signal to do the same， so place your napkin on your lap. Unfold it completely if it is a small napkin. Or in half， lengthwise （纵向地） ，if it is a large dinner napkin.
If you need to leave the table during the meal， place your napkin on your chair as a signal to your server that you will be returning. Once the meal is over， place your napkin neatly on the table to the right of your dinner plate. Do not refold it.
Use a napkin only for your mouth. Never use it for your nose， face or forehead. Use of utensils （餐具）
Start with the knife， fork or spoon furthest from your plate， and work your way in， using one utensil for each course. If soup is served， remember to spoon away from yourself. This helps stop the drips. Do not put the entire soup spoon in your mouth. Instead， fill a soup spoon about 75 per cent with soup， and sip（啜饮）it from the side noiselessly.
After finishing dinner， place the knife and fork parallel to one another across the plate with the knife blade facing inward toward the plate.
Using your fingers
Here's a list of finger foods： sandwiches， cookies， small fruits or berries with stems， French fries and potato chips， and hamburgers.
Chew（咀嚼）with your mouth closed and don't make noise； don't talk with your mouth full. Bread must be broken with your hands. It is never cut with a knife.
Don't pick something Out of your teeth. Instead， excuse yourself to the bathroom. If possible， try not to cough at the table. Do not put your elbows （肘） on the table. In France， it is essential to have both hands above the table at the same time. Do not put bones or anything else on the table. Things that are not eaten should be put on your plate.
The napkin is used only for（）. your forehead。 your mouth。 your nose。 your face。
1071年以后，塞尔柱突厥人控制了（），不允许基督教徒去朝圣。 麦加。 耶路撒冷。 小亚细亚。 罗马。
剩余价值与资本积累和扩大再生产的关系是（） 剩余价值是资本积累的源泉。 资本积累是剩余价值的源泉。 资本积累是扩大再生产的源泉。 扩大再生产是剩余价值的源泉。 扩大再生产是资本积累的源泉。
（）的方法时间较长，但肉中的营养成分及水分损失较少。 空气解冻。 水泡解冻。 微波解冻。 水冲解冻。
某教师针对不同发展水平的幼儿提供了不同难度的操作材料，这遵循了（）。
