皮皮学，免费搜题
登录
搜题
【单选题】
如图所示电路中，已知I 1 =0.3A，I 2 =0.5A，I 3 =1A则电流I 4 等于（）A.
0.2A
B.
-0.2A
C.
1.8A
D.
-1.8A
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【简答题】A driver should __ the road when . A．concentrate on; drive B．concentrate in; driving C．concentrate to; drove D．concentrate on; driving
【单选题】Never concentrate all your attention on one or two problems, ______ others.
A.
swarm with
B.
do away with
C.
to the exclusion of
D.
think nothing of
【单选题】We must ___ on our study..
A.
concentrate
B.
concentrate at
C.
concentrate on
D.
concentrate with
参考解析：
知识点：
题目纠错 0
发布
