使用热导检测器作色谱分析时,常用氢气作载气,其优点是热导系数大,便宜易得,其缺点是(),故一定要注意安全。
参考答案:易燃易爆
The chance I had been looking forward_____ at last.[ ]
A. to came
B. to come
C. to coming
D. to comes
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