用first intermediate host造句子，“first intermediate host”造句

Investigation into the ecology of first intermediate hosts of Pagumogonimus skrijabini in in Xingshan County,the Three Gorges reservoir area

Two species of snails, namely, Tricula fujiansis and Semisulcospira libertina were found, but only the former was the first intermediate host. The infection rate of snails was 0.7%(4/569).

The results confirm the first intermediate hosts are several species of Tricula, and the second intermediate hosts are Potamon chinghungense and P. hispidum.