定值调节系统是按()进行调节的,是()环调节。
参考答案:测量与给定的偏差大小、闭
At the end of the valley we turned right, and made for the summit.
A.headed for
B.went for
C.looked for
D.searched for
The monument ____ those heroes stands ____ the foot of the mountain. [ ]
A. of; at
B. to; on
C. for; by
D. to; at