【简答题】阅读理解。 Traveling Can Help Solve the Crime Problems Americans think that travel is good for you. Some even think it can help to solve one of the country's worst problems-crime. Crime worries a lot of pe...
【单选题】一衍射光栅,每厘米有200条透光缝,每条透光缝宽a=2×10-3cm,在光栅后放一焦距f=1m的凸透镜,现以波长λ=600nm的单色平行光垂直照射光栅,则在透光缝a的单缝衍射中央明条纹宽度内,出现光栅衍射光谱线的条数是()。
【简答题】颈动脉鞘内的结构有___________、___________、___________和___________。
【简答题】阅读理解。 Americans think that travel is good for you . Some even think it can help to solve one of the country’s worst problems—crime . Crime worries a lot of people . Every year , the number of crimes g...
【简答题】完形填空。 Americans think that travel is good for you, some even think it can help one of the country's worst problems-crime. Crime worries a lot of people. Every year, the number of crimes goes 1 . And m...
【单选题】Most Americans think that solid growth in 1990s can be attributed to the fact that _____.
A.
American industries have optimized structure to meet new demands
B.
US businesses have improved productivity
C.
US businesses enjoy better management than their overseas rivals
【单选题】听力原文: Most Americans think that ice cream is as American as baseball and apple pie. But ice cream was known long before America was discovered. The Roman emperor Nero may have made a kind of ice cream...
A.
They think that ice cream is very new.
B.
They know that ice cream is brought from Europe.
C.
They think that ice cream was an American idea.
D.
They don't know what ice cream is.
【单选题】1要绘制与3个对象都相切的圆,最好是( )。
A.
选择菜单 “ 绘图→圆→相切、相切、相切 ” 命令
B.
选择菜单 “ 绘图→圆→相切、相切、半径 ” 命令
D.
单击 “ 圆 ” 按钮,并在命令行输入 “ 3P ” 命令