A-A+
People did not begin to use unmanned vehicles
问题详情
People did not begin to use unmanned vehicles in undersea exploration until recently because of______.
A．the communication problem
B．the movement of waves
C．the ocean depths
D．the problem of vacuum请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：A
就为什么“人们直到最近才开始在海底探索中使用无人驾驶的遥控装置”这一问题，作者在第四段开头和第五段开头明确地给出了原因：“onereasonforthisiscommunicatingwithvehiclesinorbitismucheasierthantalkingtothoseunderwater”及“Forasimilarreason,knowingwhereyouareunderseaismuchmoredifficultthaninspace”。因此可以断定[A]是正确答案。
