a great deal“大量”a great deal后面如果要跟名词,必须加介词of,即a great deal of,
注意：a great deal of只能修饰不可数名词.
a great deal可以不加名词,这个时候它就被用作副词了.
例如：I've learnt a great deal from this book.
从这本书上我学到了很多.
另外,a great deal of 也可说成a good deal of.
shall 的回答：yes,you can/may; no,you can't
may和can could相同:Yes,...may/can/could.No,...mustn't/...'d better not/can't
must和need相同:Yes,...must.No,...needn't/don't have to
in one's thirties表示在某人三十几岁时
in 1950s则表示在二十世纪五十年代