画图说明最简单电路的组成。
参考答案:
简单电路是由电源E、导线、负载R和开关S组成,见图Ⅰ-11所示。
---Mr. Smith, ______ he have all these letters typed for you right away?
---He ______. They should be ready by 10 o’clock this morning.
A.will; must
B.shall; has to
C.need; will
D.would; ought to
在Word编辑状态下,可以通过键盘上Backspace键将已选中的文本块删除。 ( )