Join the following pairs of sentences as directed:

(a) I was tired. I did a lot of work. (use because of)

(b) He is weak in English. He is weak in Bengali too. (use 'not only...but also") 

(c) The sailor spoke very strongly. The guest stood still and listened to him. (use 'so...that') 

(d) Drink pure water. You will be healthy. (use 'in order to') 

(e) Our country is poor. We should not live in luxury. (use 'since')