甘草属于几级保护物种()
A.1
B.2
C.3
D.4
E.不属于
参考答案:B
.
The best music teacher in the school has hurt his left foot and cannot ______ tomorrow’s concert.
A.take part
B.play a part in
C.participate in
D.participate
线路上钢轨硬弯应及时整正,用于60kg/m钢轨的调直机为YZ-2型,它是YZ-1型的改进。