航空器类别的划分是依据().
A.经鉴定的最大全重时的进近程度
B.最大着陆重量和着陆构形时的失速速度的1.3倍
C.最大全重失速速度的1.3倍
参考答案:B
用所给单词的适当形式填空。
1. Miss Gao told us how to improve our _____ (speak).
2. Mr Smith is going to start _____ (teach) in China.
3. If you want _____ (study) English well, you should practice _____ (speak) it every day.
4. My job is _____ (make) the city much cleaner.
5. We _____ (make) our resolution yesterday.
牙龈上皮萎缩,组织水肿,临床表现为
A.牙龈呈暗红色
B.牙龈质地松软
C.牙龈表面光亮,点彩消失
D.牙龈色粉红且致密
E.探诊出血,疼痛