资源严重减少的主要常用野生药材物种属于几级保护物种()
A.1
B.2
C.3
D.4
E.5
参考答案:C
武汉长江二桥是世界上第一座弧线形钢塔斜拉桥,该桥全长16800m,用科学记数法表示这个数为( ).
A.1.68×103m
B.16.8×103 m
C.0.168×104m
D.1.68×104m
He broke a piece of chocolate and gave it to me before he broke the rest into pieces.
A.up; down
B.off; up
C.down; up
D.through; down