Read the passage given below and answer the question.
Food chains ‘P’ and ‘Q’ form an interconnection. ‘P’ initiates with wheat grass whose population supports a few grasshoppers, frogs and snakes.
‘Q’ starts with dead decaying leaves of wheat grass which are eaten by earthworms and then food chain is continued with frog of food chain ‘P’.
Identify the types of food chains ‘P’ and ‘Q’:
Rearrange the following parts to form a meaningful and grammatically correct sentence:
P. that maintaining a positive attitude
Q. even in difficult situations
R. is essential for success
S. and helps overcome obstacles effectively