Right and wrong should be easy to tell apart, shouldn't they?

Even cars, within a given model class, are more difficult than ever to tell apart.

The two species can be very difficult to tell apart.

They would be almost impossible to tell apart in the dark.

Despite the differences between the two species they can be hard to tell apart at sea, especially in poor light.

Some of their paintings from that period are difficult to tell apart.

Each had its own name, but otherwise they were impossible to tell apart.

Civil and military nuclear technologies are very difficult to tell apart.

He still found humans hard to tell apart by sight.

At a distance, the two national flags were hard to tell apart.