8.935≈9,8.935≈8.9都是用去尾法凑整得到的.______.(判断对错)
8.935≈9,8.935≈8.9是用“四舍五入法”得到的;
故答案为:×.
I often help my parents _____ Saturday. [ ]
A. in
B. at
C. on
仪表安装工程预算中,材料费往往占安装工程造价的()左右。
A、40%
B、50%
C、60%
D、70%