airways
A. 器官
B. 气道
C. 空气
D. 道路
What are the common signs of asthma patients?
Asthma patients often cough a lot.
B. They may also make a wheezing.
C. Some patients feel tightness or pain in the chest.
D. Severe asthma can lead to death.
What are the pathogenic causes of asthma?
A. People believe that asthma is caused by the environment.
B. People believe that asthma is caused by the air pollution.
C. Asthma is also believed to be inherited from the forefathers.
D. Asthma can be spread by the infected blood products.
目前，选用开源的虚拟化产品组建虚拟化平台，构建基于硬件的虚拟化层，可以选用（ ）
A. VMware
B. VirtualBox
C. Hyper-v
D. Xen
微信支付 
支付宝支付