書名：如題
頁數：03_120
題目：
A sturdy support beam was added to the first story of the building
for ____ reasons.
(A) structures
(B) structurally
(C) structure
(D) structural
疑問：為甚麼是D而不是C
常常在用for safety reason,...... 不是一樣用法嗎?
感謝.