to act on; to affect; action; function; activity; impact; result; effect; purpose; intent; (suffix) -ation, -tion etc, as in 用, inhibition
worker; workshop; (slang) troublesome; high-maintenance (person)
to use; to employ; to have to; to eat or drink; expense or outlay; usefulness; hence; therefore
这有很大作用。
Practice each character