长期服用苯妥英钠应注意补充
A．维生素CB．维生素EC．维生素DD．叶酸E．叶酸和维生素D
参考答案：E
It's never _______. [ ]
A. late enough to learn
B. not late enough to learn
C. too late to learn
D. no late as not learn
以下( )不属于临界资源。
A．打印机
B．非共享数据
C．共享变量
D．共享缓冲区
