Можно ли отпустить Which,whose,when,why в данных предложениях?Can you leave out Which, whose, when, why in these clauses?
6.A cheetah is a large, wild, cat-like animal which can run very fast. 7. The cheetah which we saw at the circus yesterday looked quite friendly. 8. A receptionist is a person whose job is to deal with guests and clients and so on. 9. The last time when I went to the planetarium was two years ago. 10. The reason why he is so sleepy now is that he didn't sleep last night at all.​