月球半径和地球半径之比,月球面积和地球陆地面积之比分别是多少()? ["A、1/4,1/16","B、1/4,1/8","C、1/4,1/6","D、1/4,1/4"]
试述土的击实特性。
冻土可分为季节性冻土和() ["不冻土","多年冻土","少冰冻土","富冰冻土"]
皮下注射剂的注射部位是() ["表皮","真皮","肌肉","表皮和真皮之间","真皮和肌肉之间"]
土中粘粒成分主要由亲水性矿物组成,具有显著的吸水膨胀和失水收缩两种变形特性,该种土可定名为() ["软土","黄土","冻土","膨胀土"]
我国政府明确提出到“十一五”末单位国内生产总值能耗降低()左右。