In 2007, the 7th grade science class gave the answers

1.Judge the temperature by feeling the thermometer.

2.Hot and cold 24 degrees Celsius, 24 degrees Celsius, -8 degrees Celsius, 30 degrees Celsius.

3.Thermal expansion and contraction Because each thermometer has a different role, it is designed according to their function of 27 degrees Celsius (in our classrooms).

The fault is that the thermometer touches the bottom of the cup, and B is that the thermometer touches the wall of the cup; c Fault is that the glass bubble of the thermometer does not fully contact the object to be measured.

Section 3: Scientific Observation.

1.Instrument Tools Content and Scope 2Precision Planning Research Mathematics Computing 3

Observation Instruments Astronomical Telescopes Microscope Strobe Cameras Observation Capabilities 4Phenomena & Data Textual Description **Record Graphic Record Textual Description **Record 5Nose, ears, fingers, color, status, bubbles, plastic filaments will flutter or 3 2 the same slightly c

Postcards that are perpendicular to the ground fall faster (or slower) The actual situation will vary depending on the placement of the postcard.

The speed of the fall may be related to the area size of the postcard, the angle of placement, the height of the fall, the hardness, the environment in which the experiment is located, and other factors White solid, the smell is not strong and hard BPart of the candle solid melts, the candle solid melts, the candle flame is red, the temperature is high, and there is a certain smell cWhite smoke was seen above the wick and a strong smell was smelled d

The candle burns and produces something else, covered with gauze, b, covered with gauze, and the bowl with an open mouth, cMaggots, produced by flies 11Why does a boiled egg take longer to turn than a raw egg when also turning? Inertia.

Homework is for doing, not for plagiarism, children's shoes write it yourself!

A gymnast with a height of one meter stands 3 meters in front of a flat mirror, and his image in the mirror is 3 meters away from the mirror, forming an upright virtual image, like a tall meter.

At this time, the distance between the athlete and his statue is 3 meters.

The imaging law of convex lens refers to the fact that the object is placed outside the focus and becomes an inverted real image on the other side of the convex lens, and there are three types of real images: reduction, equal size, and magnification. The smaller the object distance, the larger the image distance, and the larger the real image. The object is placed in focus, and the virtual image is magnified upright on the same side of the convex lens.

The smaller the object distance, the smaller the image distance, and the smaller the virtual image.