问个英语专四选择题73.The scientists have made an _____ study of the v

问个英语专四选择题73.The scientists have made an _____ study of the v 问三道关于语法的题目31.The scientists have made an exhaustive study of 一道单选题Scientists have made a great ______ in the treatment of The scientists sudden _____(die) made us very sad. Chinese scientists have made a great__in genetics in the pas A group of scientists _____ the west of the country. 问一道英语选择题Recently the newspapers have reported several _____ 问一道四级英语选择题All the flights( )because of the snowstorm,we had 就是一道英语选择题,Large _____ of water in the river have been pollut Scientists throughout the world have been dreaming _____ whe With the population explosion, scientists will have to _____ 英语 语法填空scientists are convinced _____ the positive effect of