“硬性”造句

这些课不是硬性规定要听的。
Attendance at these lectures is not compulsory.

参加晚祷并非硬性规定.
Attendance at evening prayers is not compulsory.

高水材料是一种新型水硬性无机胶凝材料,水灰比高达3.0.
The material with high water is a new water - hardening inorganic gelling material.