Joke Collection Website - Public benefit messages - There are numbers in the mobile phone, but why can't some numbers be displayed when calling or texting?

There are numbers in the mobile phone, but why can't some numbers be displayed when calling or texting?

The possibilities are as follows: 1. The caller's phone number is confidential

2。 I didn't turn on the caller ID myself.

3。 The function of the mobile phone itself is damaged

The landlord thinks for himself and sees what kind of possibility it is.