____ a more comfortable life, the poor couple worked hard and took on more part-time jobs.

A．Aiming at

B．Adding to

C．Relating to

D．Taking advantage of

不属于影响矽肺发病的因素是（）

A.游离SiO₂纤维的直径和长度

B.游离SiO₂类型

C.游离SiO₂含量

D.个体因素

E.肺内游离SiO₂粉尘蓄积量