【单选题】Why does the professor mention the Moon’s mantle?
A.
To explain why scientists believe that meteor impacts cannot affect the Moon’s mantle
B.
To explain what kind of information scientists hope to obtain from the mantle
C.
To point out that the Moon’s crust and mantle are made of similar materials
D.
To point out that the Moon’s mantle and Earth’s mantle have different compositions
【单选题】Why does the author use the Chinese mother's shopping experience as an example?
A.
To warn shop assistants of tough customers.
B.
To teach people how to get better service as customers.
C.
To criticize some improper shopping behavior.
D.
To show how different people's expectations of service are.
【单选题】Why does the professor discuss the instruments of the orchestra for Monteverdi's opera Orfeo?
A.
To compare the Baroque orchestra with the orchestra of today
B.
To give examples of instruments that Monteverdi invented
C.
To illustrate how different instruments helped to tell a story
D.
To explain why the orchestra was the center of Baroque music
【单选题】设有一联合体变量定义如下: union data {long w;float x;int y;char z;}; union data beta; 执行下面赋值语句后,正确的联合体变量beta的值是。 beta.w=123321;beta.y=88;beta.x=99.9;beta.z='A';