(1)①某红焰烟花的配方中包括硫,木炭粉、硝酸锶[Sr(NO3)2]等,硝酸锶中Sr的化合价为
(2)燃放孔明灯祈祷成为元宵节的新风尚,小新同学自制孔明灯,为了使它能飞得更高,更远、更安全,选择作为灯罩的材料应质轻且
(3)某市禁止燃放孔明灯,燃烧时外焰温度高达300多度,一旦飘落到加油站,液化气站,油库等地,孔明灯会
A、提供可燃物 B、供给氧气 C、使温度达到可燃物的着火点.
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2