如何防止排放履带张紧机构高压润滑油脂飞射时伤人？
参考答案：劳保穿戴齐全；作业时站于侧面操作；缓慢拧松，泄压。
—Where's Lucy?
—I'm not sure. She ________ in the school library. [ ]
A. maybe
B. must be
C. may be
D. will be
下列注射法的进针角度哪项是错误的（）
A.皮内5°
B.皮下30°—40°
C.肌肉90°
D.静脉30°
