1.A number of factors are accountable for this situation.
A number of factors might contribute to (lead to )(account for ) the phenomenon(problem).
2. The answer to this problem involves many factors.
3. The phenomenon mainly stems from the fact that...
4. The factors that contribute to this situation include...
5. The change in ...largely results from the fact that...
6. We may blame ...,but the real causes are...
7. Part of the explanations for it is that ...
One of the most common factors (causes ) is that ...
Another contributing factor (cause ) is ...
Perhaps the primary factor is that
But the fundamental cause is that ...
英文睡前故事 第89集:The Pencil
英文睡前故事 第65集:Sidney the Little Blue Elephant
英文睡前故事 第93集:Thump Quack Moo
英文睡前故事 第99集:What Does Daddy Do
英文睡前故事 第57集:Penguin Post
英文睡前故事 第55集:Nobody Laughs at a Lion
英文睡前故事 第62集:Princess Smartypants Breaks the Rules
英文睡前故事 第80集:The Bog Baby
英文睡前故事 第84集:The Hipponotamus
英文睡前故事 第73集:Tappity Tap What Was That
英文睡前故事 第92集:The Topsy Turvies
英文睡前故事 第69集:Small Mouse Big City
英文睡前故事 第63集:Ruby Sings the Blues
英文睡前故事 第86集:The Little Star Who Wished
英文睡前故事 第64集:Russell the Sheep
英文睡前故事 第102集:When Lulu Went to the Zoo
英文睡前故事 第47集:Look Out Stripey Horse
英文睡前故事 第48集:Magic Sky
英文睡前故事 第76集:That Rabbit Belongs to Emily Brown
英文睡前故事 第101集:What Pet to Get
英文睡前故事 第71集:Super Daisy and the Peril of Planet Red Fox
英文睡前故事 第97集:Twinkles, Arthur and Puss
英文睡前故事 第56集:Once There Was a House
英文睡前故事 第95集:Tiny Rannosaurus and Big Footasaurus
英文睡前故事 第90集:The Show at Rickety Barn
英文睡前故事 第75集:That Pesky Rat
英文睡前故事 第79集:The Blackest Hole in Space
英文睡前故事 第96集:Trumpet the Little Elephant
英文睡前故事 第81集:The Cow That Laid an Egg
英文睡前故事 第91集:The Star Faced Crocodile