The choice of cement for high-strength concrete should not be based only on mortar-cube tests but it should also include tests of compressive strengths of concrete at ___________ days.

The choice of cement for high-strength concrete should not be based on

1.	The choice of cement for high-strength concrete should not be based only on mortar-cube tests but it should also include tests of compressive strengths of concrete at ___________ days.
A.	28, 56, 91
B.	28, 60, 90
C.	30, 60, 90
D.	30, 45, 60
Answer» B. 28, 60, 90