填空题 Questions 20-22
Complete the sentences below with words taken from Reading Passage 2.
Use NO MORE THAN TWO WORDS for each answer.
Write your answers in boxes 20-22 on your answer sheet.

填空题 If they are too small to provide ______, the closing pod allows insects to get out.

填空题 Only the ______ is left after the Flytrap has finished digesting an insect.

填空题 Many plants cannot survive in bogs and wetlands owing to the lack of ______.