【单选题】我昨天买的钢笔将作为礼物寄给你。 The pen, _____ I bought yesterday, will be sent to you as a gift.
【简答题】Yesterday I____(寄)a present to my sister who is in another city. Tom ____(借)a pen to me last week.
【简答题】已知平行四边形ABCD中,对角线AC和BD相交于点O,AC=10,BD=8. (1)若AC⊥BD,试求四边形ABCD的面积; (2)若AC与BD的夹角∠AOD=60°,求四边形ABCD的面积; (3)试讨论:若把题目中“平行四边形ABCD”改为“四边形ABCD”,且∠AOD=θ,AC=a,BD=b,试求四边形ABCD的面积(用含θ,a,b的代数式表示).
【单选题】我昨天买的钢笔将作为礼物寄给你。
A.
The pen, which I buy yesterday ,will be sent to you as a gift.
B.
The pen, which I bought yesterday ,will be sent to you as a gift.
【简答题】已知平行四边形ABCD中,对角线AC和BD相较于点O,AB=12,AC=10 ,BD=26,则平行四边形ABCD的面积为
【单选题】(1998)关于微动脉,下列哪一项是错误的:
【简答题】如图,已知E、F是平行四边形ABCD对角线AC上的两点,并且AE=CF,请说明四边形BFDE是平行四边形。