A student measured the length of an object with a ruler with the minimum scale value of 1 mm, and made the following records: ① 18.74 cm, ② 1.87 × 10 quartic mm A student measured the length of an object with a ruler with the minimum scale value of 1 mm, and made the following records: ① 18.74 cm, ② 1.87 × 10 quartic mm, ③ 0.187 m, ④ 1.874 × 10 quadratic mm A. ① and ③ B. (1) and (4) C. (2) and (4) D. All meet the requirements

A student measured the length of an object with a ruler with the minimum scale value of 1 mm, and made the following records: ① 18.74 cm, ② 1.87 × 10 quartic mm A student measured the length of an object with a ruler with the minimum scale value of 1 mm, and made the following records: ① 18.74 cm, ② 1.87 × 10 quartic mm, ③ 0.187 m, ④ 1.874 × 10 quadratic mm A. ① and ③ B. (1) and (4) C. (2) and (4) D. All meet the requirements

If the minimum scale value (graduation value) is 1 mm, it is necessary to estimate the next digit of the graduation value, that is, 0.1 mm
So: ① 18.74cm = 187.4mm, ② 1.87 × 10 quartic mm = 18700mm, ③ 0.187m = 187mm, ④ 1.874 × 10 quadratic mm = 187.4mm
So they are ① and ④
Choose B

Careless students really careless, an assignment in the teacher out of such a problem: polynomial a minus 3y2 power - 7Y + 1, careless

Polynomial A is: 5Y ^ 2 + 4y-9 - (3Y ^ 2 - 7Y + 1)
=(5y^2-3y^2)+(4y+7y)-9-1
=2y^2 +11y -10
The correct solution is: 2Y ^ 2 + 11y - 10 - (3Y ^ 2 - 7Y + 1)
=(2y^2-3y^2)+(11y+7y)-10-1
=-y^2 +18y -11
Hope to adopt