短語詞組短語Also Be Extremely Useful 也極有用be very useful t 精通be very useful at 精通;精曉be e useful to 對…有用be also useful as 作為be very useful to understand 理解它非常有用be a useful supplement to 對……有益補充be very useful for us 對我們很有用seem to be useful 似乎有作用 返回 be useful