【单选题】Two decades after the Emerald River Dam was built, none of the eight fish species native to the Emerald River was still reproducing adequately in the river below the dam. Since the dam reduced the ann...
A.
The native fish species were still able to reproduce only in side streams of the river below the dam where the annual temperature range remains approximately 50 degrees.
B.
Before the dam was built, the Emerald River annually overflowed its banks, creating backwaters that were critical breeding areas for the native species of fish.
C.
The lowest recorded temperature of the Emerald River before the dam was built was 34 degrees, whereas the lowest recorded temperature of the river after the dam was built has been 43 degrees.
D.
Nonnative species of fish, introduced into the Emerald River after the dam was built, have begun competing with the declining native fish species for food and space.
E.
Five of the fish species native to the Emerald River are not native to any other river in North America.
【简答题】Directions: Fill in the blanks with appropriate words whose beginning letters have been given. Six consecutive days of spring rain had created a raging river running by Nancy Brown’s farm. As she trie...
【简答题】5 Good or bad? Write G or B. ► This gas won’t harm anyone. G 1 Some kinds of animals are vanishing. ____ 2 The flood water is falling. ____ 3 Famine is spreading. ____ 4 This l...