1. The atmosphere _of certain gases mixed together in definite proportions.a. composes b. comprises c. consists d. constitutes 2.While he was in the office he _doing something to doing nothing.a. preferred b. liked c. favored d. approved3.Metals_ when cooled and expand when heated.a. decrease b. reduce c. condensecondense kndensvi. 浓缩；凝结vt. 使浓缩；使压缩 d. contractcontract kntrkt, kntrktvi. 感染；订约；收缩vt. 感染；订约；使缩短n. 合同；婚约 4.Take y
