增大难度英文

the final exam will be more difficult~

The difficulty of final exam should be increased

highly/extremely difficult/hardsomething of a high difficulty level绝对精确，请放心采用。

hard一般程度的难; difficult困难的; tough棘手的;insuperable难以克服的;insurmountable难以逾越的

formal writing would be "The difficulty of the final exam should increase"(正式)more casual would be "the final exam should be harder"（非正式）