选用压力表时,最高压力刻度应为工作压力的()倍左右。
参考答案:1.5
函数f(x)=-x4+2x2+3的最大值为 .
—_________! Where is my jacket?
—_________, I don't know. [ ]
A. Excuse me, Yes
B. Excuse, Sorry
C. Excuse me, Sorry
D. Yes, Sorry