某电场的电场线如图所示,则同一点电荷放在电场中的点和点所受静电力和的大小关系是
A.
B.
C.
D.由于电荷的正、负未知,故无法判断和的大小
答案:A
第四部分: 写作(共两节,满分35分)
第一节:对话填空(共10小题;每小题1分.满分10分)
W:I had such a (76) t_______ day yesterday that I’m really starting to (77) b______ that Friday the thirteenth is unlucky .
M:Why ? What (78) h_______ ?
W:Everything went (79) w______ . For example , I had to meet an important customer in the morning and on the way to town the car (80) b______ down . When I finally got there , the customer had already left .
M:That certainly is bad luck .
W:That’s not (81) a____. In the afternoon the children asked some kids over to play and they had a pillow (82) f_______ and tore one of the pillows . When I got home there were feathers all over the (83) r_____
M:My goodness !
W:And to make matters (84) w_____ , my boss and his wife arrived while I was (85) c_______ up the house . I had forgotten that I’d invited them for dinner.
胚胎期指的是受孕后的
A.8周以内
B.9周以内
C.10周以内
D.11周以内
E.12周以内