Compared with dreamless sleep, deep dream sleep is
A、not the result of natural selection
B、less likely to appear to monkeys
C、more protective to the animals
D、at a higher stage of evolution
Task 221. In most cases of cloud-to-ground lightning, the ground'ssurface__________22. One form of lightning that is ball lightning. __________23. Cloud lightning looks like a ribbon when its lighting channel__________24. Although not fully understanding processes of lightning, man__________25. Lightening can__________A. occurs most infrequentlyB. is shifted sideways by strong windsC. strike twice or more in the same spotD. is equipped with a good knowledge of various forms oflightningE. is estimated at 20 million a yearF. is positively charged
Henry Manley's company was making enough profits to raise the workers'wages.