Questions and Answers About English Grammar. A strong verb is one in which tense is expressed by an internal vowel change, and a weak verb is one in which tense is expressed by a regular affix ( Linguistics for Everyone: An Introduction, 2013).
Jensen says scientists used to think human brain development was pretty complete by age 10. Or as she puts it, that a teenage brain is just an adult brain with fewer miles on it.. But it's not. To begin with, she says, a crucial part of the brain â the frontal lobes â are not fully connected. Really.
In the last few weeks of the first trimester, the embryo really starts to take shape. The facial structures begin to form and become recognizable. The neural tube, which will form the brain and spinal cord, develops. Little buds emerge and grow into arms and legs. Around week 8, the embryo becomes a fetus. The kidneys, liver, brain, and lungs are all beginning to function. The fingers and toes are separate and the external genitalia are formed. At 12 weeks, the fetus is about three inches long and weighs about one ounce.