This site is like KidSpiration, but it is free and easy to use. elements story, create-your-own-topic. Source: Liz Phillips. After a teacher types in the story starter, students log in to write. read, the class decides which direction the story should take. class agrees the story is finished.
Fetal development - month 1. First trimester. At the end of four weeks: Baby is 1/4 inch long. Heart, digestive system, backbone and spinal cord begin to form. Placenta (sometimes called afterbirth) begins to develop. The single fertilized egg is now 10,000 times larger than it was at conception.
During the first eight weeks, a fetus is called an embryo. The embryo develops rapidly and by the end of the first trimester it becomes a fetus that is fully formed, weighing approximately 1/2 to one ounce and measuring, on average, three to four inches in length.