问题 选择题

废弃的定影液中含有一定量的AgNO3,某课外活动小组从摄影店收集到一些废弃的定影液,准备将其中的银以单质形式全部回收.他们设计了如下的实验方案:

请判断选用A、D药品最合理的一组的是[     ]

A.Cu   H2SO4

B.Fe   AgNO3

C.Cu   AgNO3

D.Fe   H2SO4

答案

答案:D

选择题
阅读理解

Eleven leatherback turtles(凌皮龟) are swimming across the Pacific Ocean to the Galapagos Islands in a "race" that will be tracked online to draw attention to the serious situation of the endangered creatures.

The turtles have been attached with satellite communication devices that give their positions, as they head South from their nesting sites on Costa Rica' s Playa Grande beach to their feeding grounds near the Galapagos, about 1,500km away.

Online participants can choose a turtle and track its course at http://www.great turtlerace.com. The winner will be the one that travels furthest in two weeks of swimming.

There is no prize for the winner of the race, aimed at highlighting the dangers to a creature that has graced (美化) the oceans for 100 million years.

Environmentalists say 95 percent of leatherbacks in the Pacific Ocean have vanished in the last 20 years due to human activity like fishing, poaching(偷猎) of their eggs and building near their nests.

Thousands of leatherbacks nested at Playa Grande 10 years ago, but the number has dropped to below 100 in the last 5 years.

The leatherback race will not be live because the turtles left Costa Rica at different times. Instead, environmentalist group Conservation International will provide a day-to-day showing of the first 14 days of their journeys simultaneously as if they were racing.

The event will raise funds to protect Playa Grande. It is being organized by groups such as Conservation International and Costa Rica' s Environment Ministry.

68. Why satellite communication devices were attached to the turtles?

A. To prevent them from losing.                        B. To live broadcast the race.

C. To communicate with the turtles.                   D. To make sure of the turtles' position.

69. You can watch the race by _________.

A. going to the Pacific Ocean                            B. tracking its course online

C. watching the program through TV                 D. fixing some communication devices to the turtles

70. From the passage we know _________.

A. the turtles will swim 14 days from their nesting sites to their feeding ground

B. there are only eleven turtles left in the Pacific Ocean

C. money will be raised to protect the endangered turtles

D. Playa Grande is an organization by Environmentalists

71. The purpose for the text is to _________.

A. throw people's attention to the endangered ocean animals

B. accuse humans of what they have done to the ocean animals

C. warn people of the dangers to ocean creatures

D. tell people that the ocean won't be lively without turtles