往复式缩机主要由()、()、()、()、()、()等组成。
参考答案:机身,主轴,连杆,十字头,气缸,气阀
该图实线为锋线且正向西北方向移动,虚线范围内为雨区。下列关于该天气系统过境时天气状况的描述,正确的是 ( )
A.天气转晴
B.气温剧烈下降
C.连续性降水
D.狂风
The island is attractive in spring and autumn because of the pleasant weather in both seasons. [ ]
A. partly
B. merely
C. nearly
D. equally