The mountains are sparsely covered with shrubbery and trees. 山上有稀疏的灌木和树覆盖。
It is far less of a problem for sexually reproducing species because the exchange of genetic material between chromosomes can separate good and bad mutations. 理论上讲，任何数量稀少的物种积累有害变异的速度都超过了它们消灭这些变异的速度。
Broome resident Pearl Hamaguchi has never traveled far from home.But in the Sun Pictures chairs, under the deep blue night sky, she has been almost everywhere. 在澳大利亚西北部有一个叫做布鲁姆的沿海小镇，布鲁姆镇是澳洲广袤的内陆地区中一个人烟稀少的偏僻的村落。
