16.How much does it -------- to take the online training cou

选A.
句意：
参加网上培训课要花费多少?
按照句意表达,直接排除B,give 给；
sb pay some money for sth
sb spend some money buying sth/on sth
按照用法搭配,pay,spend都是用人作主语,而语境中给的主语是【it】,指代后面的真主语【to take the online training course】不定式短语,指代事物,因此排除.
cost
sth cost sb some money
the cost of sth is
用法和搭配符合语境需要.