Hamster or Gerbil?
 When you first see them, hamsters and gerbils look almost the same. In some ways they are similar. 1.   (36)   of them are soft, friendly, and lovely. 2. They are great pets, and they need exercise every day. 3. The food they like is almost the same. But there are quite a few differences.   (37)   
One way is to compare how they look. Although they can be the same size, hamsters are usually bigger than gerbils. One of the most obvious differences between hamsters and gerbils is their tails. A hamster’s tail is short and stubby. But a gerbil’s tail is   (38)       . Now look at their heads. The hamster’s head is round with fat cheeks. But the gerbil’s head is narrow, like a mouse’s. That is, the hamster’s head is   (39)   than gerbil’s.
Or you could compare habits. A gerbil often live in pairs or groups while a hamster likes to live by itself. Besides, a gerbil plays all day and sleeps at night. However, a hamster sleeps during the day. If you keep them as pets, and one day the   (40)   of little feet running on a wheel wakes you up at night, you’ll know it’s your hamster.
【題組】36.
(A) All
(B) Two
(C) Both
(D) Some