企业的特征分别是()。
A.经济性
B.开放性
C.社会性
D.独立性
E.盈利性
参考答案:A, C, D, E
解析:企业具有经济性、独立行、社会性、盈利性四个特征。
用方框中所给动词的适当形式完成下列句子
1. I _____ my teeth three times yesterday.
2. When I was a child, I _____ to be a doctor.
3. We _____ our vacation last year. We stayed at a very nice hotel.
4. Amy's grandfather _____ when he was 90 years old.
5. The concert _____ at 7:30 and ended at 10:00.
正常龈沟深度()
A.≤0.5mm
B.≤lmm
C.≤2mm
D.2~3mm
E.≤3mm