会车视距
参考答案：
两辆车相向行驶，驾驶员看到前方车辆时起，至安全会车时止，两辆汽车行驶所需的最短距离。
Most parents who are generous are good parents, but some self-centered parents are also good parents. Yet all good parents share one characteristic: they are good listeners. If all of the statements in the passage are true, which one of the following must also be true
A．All parents who are good listeners are good parents.
B．Some parents who are good listeners are not good parents.
C．Most parents who are good listeners are generous.
D．Some parents who are good listeners are self-centered.
E．(E) Fewer self-centered parents than generous parents are good listeners.
决定空间分辨率的主要因素是
A．扫描方式B．有效视野C．重建矩阵D．显示矩阵E．探测器数目
