______ come into leaf or bloom is obviously a sign of spring. 

A．Trees

B．The trees

C．That trees

D．What trees

维修浆砌石护坡勾缝脱落时，须剔除（），将缝口清除干净。

A.缝内填料

B.所有勾缝

C.砌石表面

D.加宽缝口