1. First, open your Excel.

2. Enter "Age" in cell A 1 and "Weight" in cell A2.

3. Select cell B 1.

4. Then open the data toolbar and select "Validity".

5. Select the series in the Allow option, select cells A 1 and A2 in the source, select "Provide drop-down arrow" and click OK.

6. The final effect is shown in the figure.

Excel operation should pay attention to the details of each step, and don't make mistakes carelessly. For beginners of Excel, we suggest starting with literacy.

First of all, you need to buy an introductory course in Excel, or attend a junior class in a regular computer school. In this process, learners need to understand the basic operating methods and common functions of Excel, such as inputting data, finding and replacing, formatting cells, sorting, summarizing, filtering and saving workbooks.

If learners have other experience in using application software, especially other office components, this process will be very fast.