This could be many things. It's common for young girls you have irregular periods but could also be a health problem. There is also a possibility of pregnancy if she is sexually active.
These are my suggestions for the final part of your homework: 6 - A; 7 - B; 8 - D; 9 - C; 10 - C.
The exercise follows the Sequence of Tenses rules.
For 2 the answer is C because you have two simultaneous actions which need same tense like, the Present.
<em>Key</em><em> </em><em>Nutrients</em><em> </em><em>about</em><em> </em><em>Nutrition</em><em>.</em><em> </em>
<h3 /><h3>The six essential nutrients are vitamins, minerals, protein, fats, water, and
<em>Carbohydrates</em></h3>
Answer:
I think its Affected by several external factors
Implantation, implantation<span> is the stage of pregnancy at which the already fertilized egg adheres to the wall of the uterus.</span>
