Answer: 1) is 2) consists 3) weighs 4) are 5) includes 6) constructed 7) constitutes 8) dated 9) suggested 10) raised 11) been 12) is regarded 13) was 14) was introduced 15) was added 16) is owned 17) managed 18) is owned
Step-by-step explanation:
We use simple past tense to talk about an action that has already been concluded in the past whereas past continuous tense is to highlight the actions that were done often in the past but are discontinued in the present.
In the paragraph given here, we have only used the simple present tense and simple past tense. Simple present tense ends with an 's' for example writes while past tense ends with 'ed' for example wasted.