钢粒钻进中钢粒不固定在钻头体上。
参考答案：对
--- After school, let’s go to play football together.
--- OK.________.
A. that’s settled B. You are welcome C It’s up to you. D. After you.
（）能造成人的结膜、口腔黏膜等的肿胀及充血。
A、CO
B、HC
C、NOX
D、炭烟
