Many years of hard work_______ his great success in the development of this new type of material.
A.due to
B.thanks to
C.contributed to
D.looked into
网友回答
C解析本题考查词义、词性。本句缺少谓语，应选动词。A项和B项意思都是“由于，因为”，皆为介词，故可排除；D项意为“调查，往里看”，语意不通；C项意思是“对……有贡献，有助于……”,故C项为正确