How do antibodies help to fight infections?

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work)

The table presents the average day and night temperatures in five cities. it also reveals whether a city receives substantial rainfall (wet climate) or little rainfall (dry climate). which city’s rocks are likeliest to experience frost wedging, and why? a) city a because the consistently subzero temperature would prevent water from melting b) city b because it is a wet region and the temperature fluctuates around the freezing point c) city c because it receives plenty of rain fall and the weather is moderately cool d) city d because the hot and dry weather would cause rocks to absorb water

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?