直接作用于中枢神经系统，处方量每次不超过三日常用量的药品是
A．麻醉药品B．一类精神药品C．二类精神药品D．处方药E．非处方药
参考答案：B
After you have done your homework ,____ sure there are mo careless mistakes before you hand it in .[ ]
A .try
B .do
C. make
D. take
阶梯爆破布置炮孔时，为避免漏气，影响爆破效果，炮孔不宜穿过与地面贯穿的裂缝；宜使炮孔与岩石层面和节理面（）。
A.平行
B.斜交
C.正交
e mo careless mistakes before you hand it in .[ ]