Shark and ray (鳐鱼) populations have dropped 71% in the last 50 years and many are at the risk of extinction. A new study 【小题1】 (publish) in the journal Nature found that overfishing is the major reason for the shocking global species drop.

While【小题2】 (cause) like climate change and pollution play a part, the largest impact has been overfishing.【小题3】 (press) from fishing on sharks and rays is now 18 times【小题4】 (great) than in the 1970s. Nearly three-quarters of the species studied (24 out of 31) are now threatened with a raised risk of extinction under the Red List standards of the International Union for Conservation of Nature (IUCN).

Researchers say their findings aren’t entirely【小题5】 (help). They draw public attention 【小题6】 a few success stories in the study which show that limiting fishing can help change the situation. Pacoureau, the paper’s lead author, points out many steps conservationists and policymakers can take【小题7】 (protect) the species, including the prohibition against hunting endangered species, trade limits for less threatened species, and measures to reduce deaths in fisheries targeting other species.

“【小题8】 (similar), there are many regional fishery restrictions for specific shark populations and ray protection policies【小题9】 have not yet been carried out nationally. In【小题10】 words, countries should work toward new international shark and ray protection measures but can start immediately at a regional or national level,” says Pacoureau.

Whale watching, Tadoussac, Canada

You hear a “whoosh”, see some mist(薄雾) and suddenly a whale appears. Recently discovering whales where they live 【小题1】 (become) an increasingly popular activity. Get on a boat in the Gulf of St Lawrence off Tadoussac, and you will get the best chance to spot a blue whale, the world’s【小题2】 (big) mammal.

Tea is one of the most popular drinks in the world. You make it by pouring hot water over the 【小题1】 (dry) leaves of a tea plant. For【小题2】(hundred) of years people believed that tea could cure illnesses and they used it as medicine. Today scientists know that tea contains chemicals that prevent cells from dying. Most teas have caffeine in 【小题3】(they), which makes you feel more active. Some people have problems 【小题4】(drink) tea because it can cause sleeplessness.

The tea plant 【小题5】(grow) best in tropical and temperate places【小题6】rain falls throughout the year. Teas can be grown from sea level 【小题7】about 2,000 meters, but the best quality grows in higher regions.

Tea comes from the leaves and buds (芽) of tea plants. Wild plants can be up to 9 meters high, however, on tea plantations, 【小题8】(pull) the leaves easily, people cut them back to 【小题9】bush of about a meter in height. It takes a plant three to five years before it is ready for picking.

A picker can harvest about 20 kg of tea a day. On large plantations the leaves 【小题10】(harvest) by machines, but the quality of tea is higher when the leaves are picked by hand.