生产时,烘梗丝机热资换体排冷凝水装置疏水阀后的两个()应自于常开状态。
参考答案:截止阀
Please tell your parents _____ come to the school. We've put off the meeting.[ ]
A. don't
B. not to
C. to not
D. not
李师傅制造机器零件,上午工作5小时,下午工作3小时,下午比上午少制造28个零件.
①算式:28÷(5-3)②算式:28÷(5-3)×(5+3)
问题是:______问题是:______
计算:______计算:______
答:______答:______.