以下各项检查对确定膀胱肿瘤最可靠（）
A.CT
B.B型超声
C.膀胱镜检查+活检
D.膀胱双合诊
E.尿细胞学检查
参考答案：C
The old worker insisted that he ______ old, and ______ back to the working post again.
[ ]
A. wasn't; be sent
B. wasn't; was sent
C. be not; send
D. isn't; sent
甲、乙两物体的温度分别为20℃和25℃，它们的质量之比为5：2，放出相等的热量后，甲的温度降低了10℃，乙的温度降低了5℃，则它们的比热容之比为______．
