托福听力每日一练第29天：
演讲听写训练1：
The birds u seen here in this slide are peregrine falcons(游隼).
These birds represent a success story among animals on the endangered(将要绝种的) species list. In the 1970s, the peregrine falcons almost disappeared as a result of the contamination of the food chain by the DDT in pesticide. The presence of the poison in their systems resulted in eggs too weak to support the incubating chicks. Their remarkable recovery is a result of the ban of DDT as a pesticide, aggressive captive feeding programs and their own resiliency（弹性）. The peregrine falcon is one of the fastest birds alive. They've been clocked at 140 to 200 miles per hour in successful pursuit of pray. In addition to speed, these birds fly directly into head winds（顶风）and they are capable of flying more than 600 miles per day with favorable tail winds（顺风）. today with the sophistication of telemetry (遥感勘测), the speeds of these birds can be tracked by orbiting satellites, by means of transmitters attached to the bird. For example, peregrine falcons stage in warmer climate, in other words, they spend time in the southern US awaiting hormonal changes preparing them to breed in the Arctic. Then they migrate north to the much colder Arctic regions. Birds have been tracked from Texas in late April to their nesting ground in Alaska, Canada and Greenland. Now let's move on to another species of birds, the
演讲听写训练2：
Ok, so in our last class we were discussing big bands swing music（摇摆舞音乐）. u remember this was a kind of dance music with a steady rhythm. But today we deal with style of music played by smaller jazz bands. It's called bebop. Now bebop may use all sorts of new types of rhythms, some of them very irregular. We'll talk more about that later. But first I want to talk about some of the social elements that i believe contributed to the development of bebop music. To do this, we have to look at when bebop arose and started becoming so popular, which was from the late 1930s through the 1940s, some the time of great depression write into the second world war. Now one factor that certainly help create the environment for bebop music was the decline of US economy. During the great depression, the economy suffered tremendously. And fewer people had money to spend on entertainment. Then during the 2nd World War the government imposed a new tax on public entertainment, what u might call performance tax. The government collected money on performances that included any types of acting, dancing or singing, but not instrumental music. So to avoid this new tax, some jazz bands stop using singers altogether. They started relying on the creativity of the instrumentalists(乐器家) to attract audiences. This was what bebop bands did. Now remember a lot of big bands have singers. So the instrumentalists simply played in the background and had occasional solos while the singer sang the melody to the songs, but not bebop bands. So the instrumentalists had much more freedom to be creative. So they experimented, playing the music faster and using new irregular sorts of rhythms.
演讲听写训练3：
Ur professor has asked me to talk to u today about the topic that should be of real concern to civil engineers: the erosion of the US beaches. Let me start with some statistics. Did u know that 90% of the coast in this country is eroding, on the gulf of Mexico for instance, erosion averages 4 to 5 feet per year. Over the past 20 years, there has been an increase in building along the coast, even though geologists and environmentalists have been warning communities about problems like erosion. Some way communities have tried to protect their building and roads and to build seawalls. However geologists have found that such stabilizing structures actually speed up to the destruction of the beaches. These beaches with seawalls, called stabilized beaches, are much narrower than beaches without them. U may wonder how seawalls speed up beach loss. The explanation is simple. If the flow of the beaches is gentle, the water energy is lessened as it washes up along the shore. It is reduced even more that returns to the sea so it doesn't carry back much sand. On the other hand, when the water hit the nearly vertical face of the seawall, it goes straight back to the sea with the full force of its energy and it carries back a great deal of sand. Because of the real risk of losing beaches, many geologists support a ban on all types of stabilizing construction on the shore lines.
更多托福资讯请访问》》》无忧托福网
我要报班》》新东方TOEFL课程
