简述经典HLAⅠ、Ⅱ基因组成及表达产物的分子结构。
列表比较HLAⅠ类和Ⅱ类分子在结构、组织分布和功能的特点。
1.Which of the following is true of personal software-as-a-service (personal SaaS)?
A.It involves the purchase of high quality, productivity software.
B.It is cost effective because it provides discounted rates on personal productivity software.
C.It involves paying for personal productivity software on a pay-per-use basis.
D.It ensures high levels of security as all data is stored directly on a user's personal computer.
2.Which of the following is a drawback of personal software-as-a-service (personal SaaS)?
A.It provides customers with limited options for purchasing different types of software.
B.It does not ensure high levels of privacy as data is maintained on a Web-based server.
C.It is an expensive proposition for most customers as software licenses involve high costs.
D.It hosts the software and related data offline and hence, cannot be accessed online.
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