Yes
To only like the opposite gender.
Gay people do not do this. You are thinking of Transgender people. If a person, (gay or straight) is transgendered, this can only be answered by a physician who specializes in trans-gender surgery.
Jewelry cannot be gay. Only people can be gay. If you are attracted to the same gender, you are gay. If you are attracted to the opposite gender, you are straight.
It is possible that you are the only real person in the room, but it is also possible that others are real as well. The concept of reality is subjective and can vary from person to person.
you can't. its not possible
The gender sign means either male or female. The gender sign is often used to describe a person's sex and is used to mark areas where only men or only women are allowed to enter.
It is not possible. Several (4) straight lines without lifting your pen is possible but 1 line is not.
The only way to be absolutely sure is to ask them.
2,560
A ruler has markings, a straight edge does not. In "straight edge and compass" constructions, you are not allowed to mark the straight edge. Things that are impossible using only a straight edge and compass are possible if markings are allowed (for example, it's possible to trisect an angle using a marked straight edge).
You know you are gay if you have sexual feelings for people of the same gender. If you are gay, and you are attracted to a straight friend, you need to move on. You are only setting yourself up for heartache.
The only possible way to know is to ask her.