塞门组装时塞门芯涂以适量（），托盖螺纹处缠聚四氟乙烯薄膜。
A.7057硅脂
B.89D制动缸脂
C.润滑油
D.120阀用改性甲基硅油
参考答案：B
Now China is fighting against illegal cooking oil（地沟油）, a kind of waste oil _____can cause a lot of illness.
A．which
B．whose
C．who
D．what
美术有哪些艺术功能？
