英语理解he suspected that LEDs would become as commonplace as th
3个回答

此处是USE的名词形式.再看how many,它提问的对象必须是可数名词,所以是下面提到的第三个意思:

名词 n.

1.

用,使用;利用[S][U][(+of)]

He makes good use of his time.

他能充分利用时间.

2.

使用权;使用能力[U][(+of)]

He gave me the use of his bike.

他让我使用他的自行车.

3.

用途,功能[C][U]

4.

效用;益处;价值[U]

What's the use of worrying?

担心有什么用呢?

These dictionaries are of great use.

这些词典十分有用.

5.

用法[S][U]

6.

【律】受益;受益权