正文中共有10处语言错误，请在错误的地方增加、删除或修改某个单词。增加：在缺词处加一个漏词符号（∧），并在此符号下面写出该加的词。删除：把多余的词用斜线（\）划掉。修改：在错的词下划一横线，并在该词下面写出修改后的词。注意：1.每处错误及其修改均仅限一词; 2. 只允许修改10处,多者(从第11处起)不记分.

Lately in the afternoon, the boys put up their tent in the middle of a field. As soon as this was done, they had cooked a meal over an open fire. They were all hungry and the food smelt well. After a wonderful meal, they said stories and sang songs by the camp fire. But some times later it began to rain. The boys felt tired so they put out the fire and crept into his tent. Their sleeping bags warm and comfortable, so they all slept soundly. At the middle of the night, one of the boys woke up or began shouting. The tent had flooded!

传染病的基本特征是（）

A.有传染性、季节性、免疫性和病原体

B.有传染性、病原体、免疫性和流行性

C.有传染性、流行性、季节性和病原体

D.有传染性、免疫性、地方性和病原体

E.有传染性、流行性、地方性和免疫性