测定值大于1000MPa时，应将数值修约到（）。
A.1MPa
B.5MPa
C.10MPa
D.50MPa
参考答案：C
West of our school lies our stadium, ______ about 5000 people in all. [ ]
A. seating
B. seated
C. which sits
D. sitting
砂浆的和易性包括（）。
A、粘聚性
B、流动性
C、保水性
D、耐久性
