How many _____________ are there?[ ]
A.tree
B.trees
C.a tree
答案:B
During enjoying the Mid-Autumn Festival, celebrating the harvest is an important reason, but of __________ importance is the whole family’s get-together.
A.fair
B.reasonable
C.equal
D.proper
刃磨錾子时应使切削刃高于砂轮水平中心线。( )