下列各图中所画的电场线,正确的是:
A.⑴⑵和⑷
B.只有⑷
C.只有⑶
D.⑵和⑶
答案:B
电场线起始于正电荷或无穷远,终止于无穷远或负电荷,⑴⑵和⑶错,B对。
My friend, Tom, may have missed taking the flight to Africa, ______ he can’t arrive for another hour.
A.in which case
B.in that case
C.in case
D.in any case
皮疹高出皮肤,时现时隐,搔之连片,此为
A.阳斑B.阴斑C.麻疹D.风疹E.瘾疹