验算组合梁刚度时,荷载通常取______。 ( )
You can _____ some bottles of wine, or some chocolates, or a bunch of flowers.
— ___________________
— Once or twice a week.
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧