Urgent! thank you! :D

Which group of chordates does  notpossess true backbones?                 a.  birds      b.  frogs and toads      c.  lampreys      d.  crocodilians

Lola needs to sign 6 invitations. using stopwatch that measures time to tenths of a second, it takes lola 5.3 seconds to sign her full name. going by the accuracy of the stopwatch, which is the most accurate determination for the number of minutes lola needs to sign all 96 invitations

Jasmine, at 33 months of age, is able to engage in some self-care behaviors but still has trouble with tasks such as putting on socks. a few months later, she accomplishes this same task relatively easily. the change in abilities is most likely due to