下列各组省区中，人口密度最小的是[ ]
A、湖南、江西
B、江苏、山东
C、陕西、四川
D、青海、西藏
答案：D
— I'm too tired after the long walk.
— _____. [ ]
A. You should have dinner
B. You should have a rest
C. You must see a dentist
D. You should drink some water
某条形基础，宽2.5m，埋深2.0m，作用在基础顶竖向力FK=220kN/m，采用夯实水泥土桩复合地基，桩径0.5m，桩长8.0m，水泥土试块fcu=1800kPa，单桩承载力特征值为145kN，桩间土fak=70kPa，γ=18kN/m3，计算复合地基面积置换率接近（）（β=0.9）。
A.12%
B.3%
C.2%
D.19%
