不准在轨面,枕木头,线路中心和()坐卧。
A.车前
B.车上
C.车下
D.线路两侧
参考答案:C
—Tommy, you can never let others know what I have told you today.
—Don’t worry. I will keep the ______.
A.address
B.money
C.secret
D.stone
中草药秦皮中含有的七叶树内酯(每个折点表示一个碳原子,氢原子未画出),具有抗菌作用.若1mol七叶树内酯分别与浓溴水和NaOH溶液完全反应,则消耗的Br2和NaOH的物质的量分别为( )
A.2 mol Br2 2 mol NaOH
B.2 mol Br2 3 mol NaOH
C.3 mol Br2 4 mol NaOH
D.4 mol Br2 4 mol NaOH