A third-grader calls out an answer in class, without raising his hand. The teacher says, "Is your arm broken, Johnny?" The teacher's remark can be called a(n)

Liza is an early-maturing girl who just reached menarche. She is very upset and is having a difficult time adjusting. Which of the following is the most likely reason for Liza's feelings?

a. Liza was unprepared for menarche; her mother hadn't even told her about it yet. b. All of Liza's friends had already reached menarche and she felt left out. c. Liza was well prepared for menarche and had learned a lot from her peers. d. All of Liza's siblings are boys and she feels uncomfortable.

Monozygotic twins are more likely to be concordant for homosexuality than dizygotic twins at a rate of about ________

A) 2:1 B) 4:1 C) 6:1 D) 10:1