50. The proximate causes of behavior are interactions with the environment, but behavior is ultimately shaped by
(A)hormones
(B)evolution
(C)sexuality
(D)pheromones

46. Sickle-cell anemia is a human disease that occurs as a result of what type of mutation in the β-globin gene? (A)silent(B)missense(C)nonsense(D)frameshift

47. Which of the following represents the proper order of events in embryonic development? (A)fertilization, cleavage, gastrulation, organogenesis, neurulation (B)fertilization, cleavage, gastrulation, neurulation, organogenesis (C) fertilization, gastrulation, neurulation, cleavage, organogenesis (D)fertilization, gastrulation, cleavage, neurulation, organogenesis (E)fertilization, gastrulation, cleavage, organogenesis, neurulation

48. Which of the following germ layer-structure is mismatched? (A)endoderm-digestive tract(B)mesoderm-notochord(C)mesoderm-lungs or respiratory tube(D)ectoderm-epidermis (E)ectoderm-brain

49. A doctor discovers that her patient can produce antibodies against some bacterial pathogens, but he is unable to protect himself against viral infections. The doctor suspects a disorder in her patient's (A)B cells(B)plasma cells(C)cytotoxic T cells(D)suppressor T cells(E)macrophages

1. Look at the picture. The boy in long pants is the only one who is_____. (A) f ishing (B) holding a basket (C) sitting (D) wearing a cap

2. Be _____ when you pick up the broken dishes. Don’t cut yourself. (A) careful (B) honest (C) polite (D) strong

3. The tall man over there is our new English teacher,_____? (A) is he (B) is there (C) isn’t he (D) isn’t there

4. The weather is nice and cool today. Let’s go for a _____ on the grass and enjoy some food and drinks. (A) drive (B) picnic (C) swim (D) vacation

5. Enya got up early this morning _____ she did not want to be late for her trip. (A) if (B) but (C) though (D) because

6. Larry, my American friend in Taiwan, has learned to use _____ well and can eat beef noodles the way most Taiwanese people do. (A) chopsticks (B) forks (C) knives (D) spoons