[单项选择]Desert plants ______ two categories according to the way they deal with the problem of surviving drought.
A. break down
B. fall into
C. differ in
D. refer to

[单项选择]Desert plants ______ two categories according to the way they deal with the problem of surviving drought.
A. break down
B. fall into
C. differ in
D. refer to

[单项选择]Desert plants______two categories according to the way they deal with the problem of surviving drought.
A. break down
B. fall into
C. differ in
D. refer to

[单项选择]Of the two T--shirts ,I chose


A. the less expensive
B. the least expensive
C. the least expensive one
D. the least expensive of them

[单项选择]（　）about wild plants that they decided to make a trip to Madagascar for further research.
A. So curious the couple was
B. So curious were the couple
C. How curious the couple were
D. The couple was such curious

[单项选择]How is food for plants made Food for plants is made ______.
A. from water
B. from the air in the sky
C. from the soil
D. from water, things in the soil and air and sunlight

[单项选择]After the cameraman had taken two photographs of the ants, he found they had ___________ all over his feet.
A. flocked
B. swarmed
C. gathered
D. crowded

[单项选择]

Passage Three
All whales fall into two groups, those with teeth and those without. Both beluga and dolphin belong to the suborder of toothed whales known as Odontoceti, along with porpoises, narwhals, pilot whales, killer whales and the largest toothed creature in the world, the sperm whale. Size differences among the Odontoceti are remarkable. A common porpoise will run only 4 or 5 feet in length and 300 pounds in weight; a sperm whale may be 10 times as long and 300 times as heavy. The beluga falls in between, weighing up to 2,000 pounds. And it does chirp. In fact, it makes a great variety of squeaking, whistling, and clicking sounds, which have earned it the name of sea canary.
The toothless, or baleen, whales belong to the suborder of Mysticeti. This is a group of generally large whales, formerly abundant in all the oceans of the world. Though reduced by hunting, most species are still found along the coasts of the United Stated and Canada. All but two
A. Breeding habits of whales.
B. Differences between whales.
C. Efforts to preserve whales.
D. The intelligence of whales.