双基限时练(十九) module 5 section ⅲ 基 础 夯 实 ⅰ.短语填空 break down; as far as; rely on; up and down; up to; put out; on the contrary; knock out; by mistake; make sure 1.mr. white may be at home, but you'd better call and ____________. 答案 make sure 2.these psychological barriers are difficult to ____________. 答案 break down