秋播甘蓝作春早熟栽培时，容易出现（）？
A、结球不紧实
B、采收期偏晚
C、品质差
D、未熟抽薹
参考答案：D
Many people in Haiti died from the earthquake because they didn’t have to immediate rescue. [ ]
A. access
B. admission
C. approach
D. attention
将1．1g某钢样在纯氧中完全燃烧，得到0．0121g二氧化碳，则此钢样中碳的质量分数为( )
A． 1．3％
B． O．3％
C． 3％
D． 1．21％
