He has worked in the factory _____ five years ago.[ ]
A. for
B. at
C. since
D. about
答案:C
A.太阳表面温度很高
B.太阳活动对地球没有影响
C.太阳体积比地球小
D.太阳是地球的一颗行星
当电脑加油机停止工作,打开油枪开关把,油枪嘴漏油是副阀的故障。()