Large scale testing of methanol as a primary engine fuel continues, with impressive results. 我们继续进行大规模试验，将甲烷用作基本动力燃料，取得了令人振奋的结果。
Evidence from large ongoing trials is needed to establish low selenium concentrations as a cardiovascular disease risk factor. 把低硒浓度作为心血管疾病的一个危险因子还需要开展大规模试验的证据来确立。
