Explanation

Birds have a right systemic arch but mammals have a left systemic arch.

in birds left systemic arc does not occur and the single aortic arc represents the right systemic arch.

Explanation

The metallic and non-metallic character of p-block elements varies as follows:

Along the period the metallic character decreases, whereas the non-metallic character increases.

It is because on moving across the period, the atomic size decreases due to the increased nuclear charge, and hence, ionization energy increases.

Explanation

CS2 + 3O2 --------> Co2 + 2SO3

CS2

= 12 + 64

= 76 /1

= 0.1limiting reactant

O2

= 12.8 / 32 

= 0.4/3

= 0.13

Explanation

After a long day at work, Sarah found solace in her favorite book, escaping into a captivating world 

ایک طویل دن کام کرنے کے بعد، ساعہ کو اپنی پسندیدہ کتاب میں سکون ملا، ایک دلفریب دنیا میں فرار

solace means   سکون

solace is best to keep the meaning of "Sarah rest" 

if we select another option It will change the whole sentence so option "A" is correct 

Explanation

Protonephridia or flame cells are the excretory structures in Platyhelminthes (Flatworms, e.g., Planaria), rotifers, some annelids

Explanation

Ester, which is R-CO-OR, is the functional group for esters. 

Esters are formed by reacting carboxylic acids, R-COOH, with alcohols, R-OH.

Explanation

suitable response to the question: "He was your day at school" 

it was great, thanks for asking!

other option is not suitable according to the question

Explanation

Stearic acid ( STEER-ik, stee-ARR-ik) is a saturated fatty acid with an 18-carbon chain.

The IUPAC name is octadecanoic acid.

Explanation

because amoeba moves with the help of microfilaments

Microfilaments (actin filaments) are the filaments that are present in the cytoplasm of the cells (eukaryotic) and they forms a part of the cytoskeleton

Explanation

Hydrogen bonds must be broken for water to evaporate.

Water molecules with high kinetic energy evaporate; the remaining molecules are cooler.