环管工艺聚丙烯装置丙烯闪蒸罐的料位是用()测量。
A、钴60
B、铯137
C、镭
D、铀235
参考答案:B
"Well done!" the teacher patted the shoulder of the student, _____ with a smile on his face. [ ]
A. satisfied
B. being satisfied
C. having satisfied
D. satisfying
对置式圆盘耙