英语语法分析

The morphological characteristics of the cercaria are described.

同时对尾蚴形态特征作了描述。

With the action time of the drug extending, the mortality of cercaria increased(P<0.01).

不同剂量组的尾蚴平均死亡率均随着药物作用时间的延长而增大（P<0.01）。

Objective To evaluate the protective effect and acute skin irritating reaction of anti cercaria emollient cream (ACEC) from infection of S.

目的实验评价新型涂肤防护剂—防蚴润肤霜防御日本血吸虫尾蚴感染的效果，并了解其对皮肤的急性刺激反应。