Thiskindofplantisver的精選

問題詳情：詞彙題；根據句意及漢語提示完成單詞。1．Thiskindofplantisvery______(稀少的)．It'sdifficulttofindit.2．Scientistsaredoing______(研究)onhowtocleanthepollutedriver.3．This______(情況)oftenhappenstopeoplewh...