未知题型 Although they plant trees in this area every year, the tops of some hills are still _______. A) blank B) hollow C) vacant D) bare

未知题型 I have heard both teachers and students _______ well of him. A) to speak B) spoken C) to have spoken D) speak

未知题型 These two areas are similar _________ they both have a high rainfall during this season.A) to that B) besides that C) in that D) except that