工矿企业常见的职业病——硅肺的病因是：当肺吸入硅尘(Si0₂)后，硅尘被吞噬细胞吞噬。由于吞噬细胞功能受阻，而使肺功能损伤的细胞器是（    ）

根据下列小题描述，从A-F中选择各位感兴趣的信息。（其中有一项多余）

① ____ Tom is looking for his schoolbag. He wants to do his homework.

② ____ Mike can't find the model plane. He is worried.

③ ____ Linda lost her ID card. She is asking her friends about it.

④ ____ An English book is in the teacher's office. Is it yours?

⑤ ____ Some keys are in the computer room. Call Mary if you lost keys.

计算

$-2^{-3}-8^{-1}\times {\left(-2\right)}^{-2}\times {\left(-\frac{1}{2}\right)}^{-2}\times {\left(\mathrm{\pi }-3.14\right)}^0$

a，b是同一平面内不重合的两条直线，则直线a与直线b的位置关系是（　　）