Does the UFO really ___________?
A: exist
B: existing
A: exist
B: existing
举一反三
- 选择更为合适的一项填入空格。 Heaven and hell ______ in this world. (exist; are existing)
- She’s been receiving ___________ phone calls lately. A: threatening B: existing C: threat D: exist
- What does the Kyoto Protocol exist as? （ ）
- Which of the following does not exist in universities?
- To save (保存) the changes in an ______ file, you need to save this file. A: exist B: existed C: existing D: existence