The required compressive strength of PCC is measured at
A: 3 days
B: 7 days
C: 14 days
D: 28 days
A: 3 days
B: 7 days
C: 14 days
D: 28 days
举一反三
- How long is the Spring festival? A: 7 days B: 3 days
- How long should children be quarantined at home after they have measles？ ( ) A: 10 days B: 7 days C: 5 days D: 15 days
- How old is the new calf that Laura sees? A: 2 days old. B: 3 days old. C: 4 days old. D: 5 days old.
- 2 How long will the order take to arrive A: 3 days B: 4 days C: 5 days
- The secretary will contact you _____. A: for three days B: in three days C: about three days D: at three days