TPO5中又有一句不理解。。望大家指教

zhangxin0804UID: 3081795

TPO5阅读  Minerals and Plants


Scientists have known for some time that certain plants, called hyper accumulators, can concentrate minerals at levels a hundredfold or greater than normal. A survey of known hyper accumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of choice. Hyper accumulators run the entire range of the plant world. They may be herbs, shrubs, or trees. Many members of the mustard family, spurge family, legume family, and grass family are top hyper accumulators. Many are found in tropical and subtropical areas of the world, where accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial pathogens.


画红线的句子。。。。的时态该如何分析啊？特别是cadmium后面的be动词,are。。。。还有这红线句子，该怎么翻译呢？
请大家指教。。。。

fly0022UID: 3002615

一个关于已知的hyper accumulator的调查确认，75%的hyper accumulator会积聚 nickel, cobalt, copper, zinc, manganese, lead，并且 cadmium 也是一种。 我这么理解的。

zhangxin0804UID: 3081795

前半部分是过去时态，后半部分be动词是are。。一般时态。。该怎么解释呢？

zhangxin0804UID: 3081795

自己再顶个~