Which of the followowing does paper burn in?A.CO2 B.N2 C.O2
Which of the following does paper burn in?(写出方程式)
Which of the following does paper burn in?___
我们呼出的气体中主要含有:A、CO2和O2 B、N2和O2 C、N2和CO2 D、CO2和H2O
下列气体不适宜冲入食品袋的是A N2 B O2 C CO2 D空气
下列气体中,化学性质最稳定的是:A、O2 B、N2 C、CO2 D、He
下列哪些是保护气?A、N2 O2 B、N2 Ar C、CO2 CO2(有可燃性)D、N2 H2(有可燃性)
All the things?paper.a.is made of /b.is made in/c.are made o
一定量的空气依次通过足量石灰水及浓硫酸,分别除去的是 A.N2和O2 B.N2.O2、和稀有气体.C.CO2、水蒸气
空气中含量最多,并且化学性质又比较稳定的是 A.CO2 B.O2 C.N2 D.H2O蒸汽
How can you stop the fire _______.a.of burning b.to burn c.f
In the bag he found a piece of paper on which were written s
how much does this kind of paper cut ___?A.spend B.cost C.pa