带煤气作业时，距离工作场所（）米内，严禁火源并应采取防止着火措施。
A、20
B、30
C、40
参考答案：C
根据汉语意思写出正确的单词。
1. I (摘) flowers in the park tomorrow.
2. Do you like to swim in the (海洋)?
3. (沙滩) have sand.
4. Mr. Green (教) us English last term.
5. My father is a . He carefully. (开车)
5/2， 9/4， 13/6， ( )
A．15/8
B．8/9
C．17/8
D．9/8
