Why is it _____ he can’t get along well with his classmates?
A./
B.this
C.that
D.it
答案:C
青少年期后逐渐萎缩()
A.骨髓
B.胸腺
C.淋巴结
D.脾
E.黏膜相关淋巴结组织
在图示电路中,当开关S闭合后,流过开关S的电流I为()。
A.1mA
B.0mA
C.无法判定
D.-1mA