【单选题】为了探讨不同训练方法对提高耐力素质的效果,现将48名基本条件相似的男生随机分成3组,进行不同方法的训练,用1500米成绩反映训练效果。请问指标是( )。
【单选题】According to the passage, which of the following was an obstacle to the development of the icebox?
A.
Competition among the owners of refrigerated freight cars.
B.
The lack of a network for the distribution of ice.
C.
The use of insufficient insulation.
D.
Inadequate understanding of physics.
【单选题】Which of the following is NOT mentioned as an obstacle of humanitarian assistance in Somalia?
C.
Operational challenge.
【单选题】为了探讨不同训练方法对提高耐力素质的效果,现将48名基本条件相似的男生随机分成3组,进行不同方法的训练,用1500米成绩反映训练效果。请问因素是( )。
【单选题】According to the passage, which of the following posed the biggest obstacle to the development of military forts?
B.
Shortage of materials.
C.
Attacks by wild animals.