Sentence:  There have been , indeed , <WSD>many</WSD> important and valuable gains from the development of our present scientific view of the world for which we may be rightly grateful . 
Meaning of the word marked with <WSD> tags:  a quantifier that can be used with count nouns and is often preceded by `as' or `too' or `so' or `that'; amounting to a large but indefinite number