Part A
Directions:
Your friend Xiao Ming saw you off on your trip to another city. Write a letter to him. In the letter, you should
(1)express your thanks;
(2)tell him you had a pleasant trip;
(3)tell him your next plan there.
You should write about 100 words.
Do not sign your own name at the end of the letter.
Use "Li Ming" instead. You do not need to write the address.
交换两个杯子A和B的液体,正确的算法是()。
①将A杯中的液体倒入空杯C
②将B杯中的液体倒入A杯
③将C杯中的液体倒入B杯
已知
a
=1,
b
=2。
(1)若a∥b,求a·b;
(2)若a、b的夹角为60°,求
a+b
;
(3)若a-b与a垂直,求当k为何值时,(ka-b)⊥(a+2b)。
设a,b,c是任意的非零平面向量,且相互不共线,有以下结论
①(a·b)·c-(c·a)·b=0;
②|a|-|b|<|a-b|;
③(b·c)·a-(c·a)·b不与c垂直;
④(3a+2b)(3a-2b)=9|a|2-4|b|2,
其中正确的是()。
当执行下面语句后,B的值为()。
B=1
If B>0 Then B=B+1
If B>1 Then B=0
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