True or false, an implicitly unwrapped optional variable must have an exclamation mark affixed after it every time it is used. 答案选项组

A.) generate scaffolding to create database for your application. develop all the entities identified in assignment #2. add any additional that may be identified later. b.) add data validation rules to the models that are appropriate for your application and data. c.) create links for each scaffold in the header section. part 2: application updates [30 points] a.) add two additional views to the "home" controller you created in assignment #1. b.) the two views should be named as “privacy" and "". c.) link the two newly created views in the footer section. hint: you would need to modify the “home" controller definition and create “privacy. html. erb" and “.html. erb" files in appropriate locations.

Which best describes the role or restriction enzymes in the analysis of edna a. to break dna into fragments that vary in size so they can be sorted and analyzed b. to amplify small amounts of dna and generate large amounts of dna for analysis c. to purify samples of dna obtained from the environment so they can be analyzed d. to sort different sizes of dna fragments into a banding pattern that can be analyzed

You can apply several different worksheet themes from which tab?