[听力原文]
Mr. Jones: What materials were used for road surfaces during the last century
Engineer: Usually they were gravel and macadam. Tars and asphalt were originally used only as coverings, but later they were used as binders and finally as hot mixtures.
Mr. Jones: Concrete is a modem material as far as road - building goes, isn’ t it
Engineer: Relatively speaking. But you might be surprised to know that a concrete road was built as early as 1893 in Ohio. But it was only 5 miles long. More extensive projects were not undertaken until much later, around 1912 or 1913.
Mr. Jones: This was because of the increase in traffic
Engineer: That’ s right. Especially in the use of heavy tracks. More rigid pavements, such as concrete and brick, became a necessity. For light traffic, though, water-bound macadam, gravel, sand clay, and bituminous mixtures were still used.
Mr. Jones: What are turnpikes usually made of
En
A. Gravel.
B. Asphalt.
C. Macadam.
D. Concrete.
In a new study about the way kids learn math in elementary school, the psychologists at the University of Chicagol Sian Beilock and Susan Levine found a surprising relationship between what female teachers think and what female students learn: If a female teacher is uncomfortable with her own math skills, then her female students are more likely to believe that boys are better than girls at math.
"If these girls keep getting math-anxious female teachers in later grades, it may create a snowball effect on their math achievement," said Levine. In other words, girls may end up learning math anxiety from their teachers. The study suggests that if these girls grow up believing that boys are better at math than girls are, then these girls may not do as well as they would have if they were more confident.
Just as students find certain subjects to be difficult, teachers can fi
A. Girls comfortable with their own math skills are better than boys at math.
B. Girls uncomfortable with their own math skills are not as good as boys at math.
C. Female teachers’ math skills have influence over girl students’ math skills.
D. Female teachers’ confidence in their math skills is related to girl’s math skills.
我来回答: