试剂盒标准品平行样的要求（）是单样。
A、不可以
B、可以
C、视情况而定
参考答案：A
He ______ in his English test paper last week. He was very satisfied with himself.[ ]
A. makes some mistakes
B. make a mistake
C. made many mistakes
D. made few mistakes
外墙面装饰构造中，( )构造做法是：一层底灰，一层面灰或不分层一次成活。
A．初级抹灰 B．中级抹灰 C．高级抹灰 D．普通抹灰
