用ping命令可以判断到远端计算机的网络是否畅通,退出该命令按Esc键。()
参考答案:错
We’d better not leave until the play ends, for the last _______ of the play is very important.
A.scene
B.sight
C.scenery
D.view
已知某反应的各物质浓度数据如下:aA(g)+bB(g)
2C(g)
起始浓度(mol/L):1.5 1.0 0
2s末浓度(mol/L):0.9 0.8 0.4
则①a=______,b______.②2S内B的反应速率=______.