(1)原式=22-2-22+233
=22-2-22+2
=0;
(2)原式=3+1+33-1
=43.
I could hear voices but I couldn’t ______ what they were saying.
A.turn out
B.pick out
C.work out
D.make out
对于多发性硬化的描述,下列正确的是()
A.进行性加重比缓解复发更为常见
B.在我国一般不累及视神经
C.多数为急性发作,类似脑中风
D.首选的治疗是免疫球蛋白
E.是中枢神经系统白质的炎性脱髓鞘疾病