Please help me with these sentences i have just encountered in my homwork

English as a Second Language English Vocabulary, Grammar and Idioms
1

I. Identify the mistake of the sentence.
The [u]males/u can grow up to (B) 13 meters length © and weigh (D) 10 tons

I suppose that A and C are also incorrect? so what should i choose? In (A) must we write “The male or Males” instead of “The males”? And in © must we write “in length” or can we omit the preposition?

II. Rephrase the following sentence with the given word.

He used to be a teacher, so he really knows what it’s like in the classroom (FIRST-HAND)
–> He has first-hand experience of teacher, so he really knows…
–> He has first-hand experience of the classroom
–> He has first-hand experience of being a teacher, so he knows…
WHICH OF THE SENTENCES ABOVE SOUNDS MORE NATURAL FOR A NATIVE SPEAKER?

2

  1. “The males” is OK. “length” should be “in length”.

  2. The first option is incorrect (“teaching” in place of “teacher” would be correct). The second and third options are both possible in themselves. However, assuming the continuation in both cases is meant to be “… so he (really) knows what it’s like in the classroom”, the second would be repetitious and the third preferable.