What are the shortest length unit and the longest length unit? Be sure to be accurate!

The shortest is nanometer (not sure), the longest is light years

What does PCs mean, a number or something

Yes, it's still me

PCs is a unit name. What does it mean in Chinese?
If the title, please have a cultural person to help translate

PCs is the abbreviation of a unit
That is, pieces, pieces, chapters, sheets, strips and sets
PCs is a unit of quantity (usually plural). For example, the output of a certain brand of computer is 350 PCS / W, which means 350 computers of that brand are produced every week

What does PCs unit mean

It can be said that it is a unit of quantity, not a unit of measurement. When goods sold abroad need to measure each unit of goods, PCS unit should be used. Especially for sellers who do foreign trade on eBay, the world's largest online trade website, PCS unit of measurement will be used in the transaction process
In addition, PCS also means shipping surcharges. In international trade, PCS shipping surcharges refer to the additional expenses or economic losses incurred by the ship in the transportation of goods due to various reasons of the ship, goods, port and other aspects. In order to compensate for these expenses or losses, the ship stipulates the additional charges in addition to the basic rate, which is called surcharges
PCs surcharge
According to different requirements, the requirements for surcharges are also different. Here we are
1. BAF fuel surcharge, most routes have, but different standards
2. SPS Shanghai Port Surcharge (port 9, 10)
3. FAF fuel price adjustment surcharge (Japan route only)
4. Yas Yen Appreciation Surcharge (for Japanese routes only)
5. Gri comprehensive rate increases surcharge, is generally Europe, South America routes, U.S. routes
6. DDC, IAC direct surcharge, the United States and Canada routes
7. IFA temporary fuel surcharge, temporary use of some routes
8. The Panama Canal surcharge, the United States route, central and South America route use
9. Orc local export surcharge, similar to SPS, is generally used in South China
10. The fuel surcharges of EBS and EBA are generally used by Australian routes, while EBA is generally used by African routes and Central South American routes
11. PCs port congestion surcharge is generally used by some ports in Israel, India and Central South America
12. PSS peak season surcharge, most routes in the transport season may temporarily use
There are many types of surcharges, and new surcharges will be cancelled or formulated as some circumstances change. Here are some common types of surcharges:
1. Bunker surcharge or bunker adjustment factor (BAF)
2. Devaluation surcharge or currency adjustment factor (CAF)

If the circle X & # 178; + Y & # 178; - 4x + 6y = 0 and the circle X & # 178; + Y & # 178; - 6 = 0 intersect at two points AB, then the equation of the vertical bisector of AB is

"X & # 178; + Y & # 178; - 6 = 0" should be "X & # 178; + Y & # 178; - 6x = 0". By subtracting the two circular equations, we can get 2x + 6y = 0, that is, x + 3Y = 0. This linear equation is the linear equation of line AB, then we can know that the slope of the vertical bisector equation of line AB is k '= 3

Add appropriate operation symbols or brackets between the following four 4 to make both sides of the equal sign equal. 4 () 4 () 4 () 4 = 4
4*（4-4）+4=4

4^2+4^2/(4+4)=4

Find the volume of an arch of cycloid x = a (t-sint), y = a (1-cost), y = 0, rotated around the straight line y = 2A. How to draw the cycloid?

There are many kinds of cycloid, this is one of them: linear cycloid - imagine a point on the outer edge of the bicycle wheel. In the process of straight-line progress of the bicycle, this point is the track of the space between two landings. The ground distance between two landings is the length of one circle of the wheel
The volume is calculated as follows: the graph is symmetric with respect to x = π A & nbsp;, so

If you read a book, you can read an average of 15 pages a day in the first five days, and plan to read 17 pages a day for the rest. How many days can you finish reading it?

It's not right. There is no condition for how many pages of the book

P is any point of the ellipse x ^ 2 / 25 + y ^ 2 / 16 = 1, F1, F2 are the left and right focal points, (1) if the angle f1pf2 is 60 degrees, find the value of | Pf1 | * | PF2 |?
(2) Find the maximum value of | Pf1 | * | PF2 |

(1) Let | Pf1 | = n, | PF2 | = m, then n + M = 10
And N & sup2; + M & sup2; = (n + m) & sup2; - 2nm = 10 & sup2; - 2nm
And | F1F2 | = 8
According to the cosine theorem, cos60 ° = (n & sup2; + M & sup2; - 8 & sup2;) 2nm
1/2=（10²-2nm-8²）/2nm
The solution is nm = 12
So at this time | Pf1 | * | PF2 | = 12
(2) The focal radius formula of ellipse: the distance from P to F1 is a + ex, and the distance from P to F2 is a-ex, where e is the eccentricity and X is the abscissa of any point on the ellipse, then x ∈ [- A, a]
In this problem, a = 5, B = 3, C = 4, then E = 4 / 5
The focal radius formula is: | Pf1 | = a + ex = 5 + (4 / 5) x, | PF2 | = a-ex = 5 - (4 / 5) X
|PF1|*|PF2|=[5+(4/5)x][5-(4/5)x]=(-16/25)x²+25
∵x∈[-5,5]
So the maximum value is 25 when x = 0
When the minimum value is x = - 5 or x = 5, 9 is obtained

Exercises! Not papers

who_____ the boy's mother?(be)
The answer is

What are the shortest length unit and the longest length unit? Be sure to be accurate!