对计量标准考核的目的是()。
A. 确定其准确度;
B. 确认其是否具有开展量值传递的资格;
C. 评定其计量性能;
__________he presented her at the dance party was an engagement ring
A. That
B. What
C. When
D. How
Let’s listen to the radio program that the teacher mentioned,_______?
A. do we
B. shall we
C. don’t we
D. will we
His parents ______last week, the child has no one to look after him.
A. having died
B. died
C. dead
D. having dead