新浇筑的（）达到1.2N/mm2前，不得在其上踩踏或安装模板及支架。
参考答案：混凝土强度
It is essential that these application forms ______ back as early as possible.
A．must be sent
B．will be sent
C．are sent
D．be sent
经营良好、利润率高的企业，即使要迅速扩大经营规模，也不一定会遇到现金短缺的问题。 ( )
