Nowadays, new job opportunities are in great need because a number of people are ____. [ ]

A. out of date

B. out of work

C. out of breath

D. out of place

书虱体长1mm～1.5mm，扁平长椭圆形，身体（），灰白色或黄褐色；头大，复眼较小；成虫，若虫均无翅；后足腿节扁平膨大。

A、柔软不透明

B、柔软半透明

C、骨化透明

D、骨化不透明