React experts for help?

Question

JavaScript

I failed the interview because of 5 React tests. I can't find the right answers for myself, help!
Which of the following is true about keys in React ?
There may be MORE then ONE right answer !
1. React keys are useful when working with dynamically created components
2. Setting the key value will keep componennts uniquely identified after the changes
3. React will use the key values ​​to keep track of each element
4. If key is present, is always supplied directly to the component as property
What visual design guidelines must be used to build web UIs with ReactJs?
1. None
2. Material design guidelines
3. Flat design guidelines
4. Facebook design guidelines
5. Twitter design guidelines
Which of the following is the correct way to create links for the react component ?

1.<a href={'https://www.facebook.com/'}>Link1</a>
2.<a link-to={testContainer}>Link1</a>
3.<a href={[to-component]}>Link1</a>
4.<a href-to={'https://www.facebook.com/'}>Link1</a>

Static object allows the defining of static methods means that these methods do not have access to or ?
1. render,props
2. state,class
3. class,component
4. props,
state
1. inline
2. flex
3. block
4. browser dependent
5. none
6. inherit
7. inline-block

Answer 1

1.3
2.1
3.1
4.4
5.4

Answer 2

google