A normal, full-term pregnancy can range from
37-42 weeks. It's divided into three
trimesters. Each trimester lasts between 12
and 14 weeks, or about three months.
Specific changes occur to the fetus during
each of these trimesters.
Which of the following events occurs during
the 3rd Trimester?

A. Fingers and toes form.
B. The lungs fully develop.
C. A heartbeat can be heard with a stethoscope.
D. The cardiovascular system develops.

15 ! come and answer! a(n) disease is caused by a pathogen and can spread among organisms. a infectious b noninfectious c toxic d contaminated

Food webs - transferring energy and matter from one level to another. here you see four food webs. one or more are incorrect. which food web(s) show the correct sequence of organisms, from start to top level consumer? a) a b) d c) c d) a and d

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a. one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b. one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c. one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.