I am a teacher, and I would like to ask Excle questions!!

Please create a table, column A is the device number of 1-1000, column B starts with the use of this number in other tables, for example, enter the formula in B2 to determine whether the number of A2 appears in column A in the "Device One Workbook" sheet1 worksheet:

if(countif([Device One Workbook]sheet1!a:a,a2)>0,"Used","")

Other tables can be judged on columns such as C and D, and if the number has been used, the new ones will not be reused.

1.Outlook Express is Microsoft's mail application that is installed by default on the operating system. If you have never set up an account and pop3 address for this app, it will not be able to receive any information.

If it opens inexplicably, the landlord still thinks that there is no virus?

2.Well, that's maybe what's the suffix for. The eml file caused it to boot up, so what's going on with this? Attach in the message. The exe is also quite unusual.

3.Finally, if all the excel files in the shared folder cannot be opened (including the past excel documents), can the excel documents that are not in the shared folder be opened normally?

a) If you can, try to copy the excel document in the shared folder first;

b) If you can't do it, then see if there is any change in the excel template file, or simply delete the template file, and then try again.

It's best to tell everyone the results of the above tests and see if you can inspire them.

Outlook Express is a software used by Microsoft to send and receive emails, which can be regarded as a condensed version of Outlook, which is relatively simple and primitive.

If it weren't for a malicious virus attacking your computer via email, it wouldn't have caused this problem. You seem to have asked this question many times before, based on your previous ** plus this email, I feel that you are very likely to be poisoned, don't believe too much in 360, it is recommended to find professional antivirus software or company IT personnel to solve it. The sender's mailbox is yahoo.,Obviously from the Internet.,And the text of his theme is comming.,It's obviously a hint and a provocation.,The attachment contains an exe execution file.,90% of it is a virus program.。

All in all, the probability of you being poisoned is 99%.

It's okay to lower the security level in the mailbox. Option --- safe, choose the one that is not so safe, in fact still Wei safe.

The same column of data. Why is the color different?

Visually see that the colors of the columns on your picture are the same.

Suppose the formula is:

Array, the second question is not understood.

What is the maximum number of levels? Post it to me for easy debugging.

I know, use the vlookup function. The following are examples of use.

Table I. <>

Table II. <>

In the third column of table I, the amount corresponding to table 2 is found based on the data in the first column of table I. That's it.

How to use the formula, as shown in the following figure, the first cell selects the column of the two tables with the same features, the second cell selects the entire content of the second **, the third cell fills in 2 (represents the data of the second column of the second **), and the fourth cell fills in true (means exact search).

Seeking, pure hand-playing, the experience taught to us by university teachers.

Set sheet1 a-business number and b-name.

Set sheet2 a-business number and b-amount.

Add column C (first name) to Sheet2

The formula for c2 is:

lookup(a2,sheet1!a2:a5,sheet1!b2:b5)

Note: Columns A in Sheet1 and Sheet2 must be in order, otherwise an error will occur!!