"Two bottles of juice is / are fifty dollars." "Two pounds of beef is / are fifty dollars."
動詞部分使用 is 還是 are？
經查詢《東華當代文法》與相關網站，得到以下解釋：
表示時間、距離、重量、錢數等的名詞，如被當做是總數，則用單數動詞；但是，
若被用以表示個別單位中的一分子，則用複數動詞。例：
(1) Seventy dollars is too much to pay for that box.
(2) Millions of dollars were spent on the project.
(3) Three yards of material was used to make his coat.
相關雜誌、報刊實例：
(1) 25 Million Pounds of Beef Is Recalled. —The New York Times
(2) Each year, approximately 35 million heart-shaped boxes of chocolate are sold for
Valentine’s Day. —News and Culture Weekly
因此，計量詞在句中擔任主詞時，其後應該使用單數或複數動詞，需視該句意強
調的重點。在 two pounds of beef 中，如果語意上強調 beef 的量值，表達的重點
仍在 beef，因此語意上會視為單數。在 two bags of beef 中，如果強調是「那二
袋」，而非 beef 有二袋之多，則會使用複數。