— These boxes are too heavy for me to carry.

— Here, I’ll give you a hand ________ them.

A．for

B．to

C．with

D．by

关于恙虫病流行病学的叙述，错误的是()

A．恙螨是此病的传播媒介

B．人群普遍易感

C．病后有巩固的免疫力，不会再次感染

D．多发生于夏秋季

E．多为散发