For example, in Roman times, engineers discovered that if the upstream supports of a bridge were shaped to offer little resistance to the current of a stream or river, they would last longer.
例如，在罗马时代，工程师们发现如果桥的上游的桥墩建成对目前河流水阻力小的形状，桥墩的寿命会更长。
2
Objective To appraise the relationship between fluconazole resistance and expression of the CDR1 gene upstream regulation sequence.
目的探讨白念珠菌耐药基因CDR1基因上游调控序列对氟康唑耐药的影响。
3
Objective:To investigate and compare the antibiotic resistance condition of the thermotolerant coliform isolated from the side situated upstream and downstream from hospital sewage discharge point.