I want to connect 2 SHT25 to measure 2 sets of temperature and humidity at 2 different sites . How should I connect it to Raspberry Pi 3. Thanks for your help
The SHT25 has an I2C interface. Use this I2C interface to connect the sensors to the Raspberry Pi. There are many online examples, and sample code; here's two that look reasonable:
EDIT - 20190703:
As Dmitry has pointed out in the comment, you will need to overcome a limitation that's "built in" to the SHT25 chip: It has one, and only one, I2C address available. And since you indicated you wish to interface two (2) of these sensors to your RPi, this poses an additional hurdle. As I see it, you have two options to clear this hurdle:
Use an I2C multiplexer device (as suggested by ttfong01 in the comments): There are a variety of resources available online to help with this if you wish to consult them (here's one example)
Use a temp/humid sensor that provides at least two I2C addresses: In my opinion, this is the cleaner, simpler solution. One such sensor is the DHT31; it offers two user-selectable I2C addresses. The address is selected simply by tying the ADDR pin to logic high or low. If you need more than 2 addresses, this is also possible (refer to the data sheet for details).