如圖，△ABC中，∠ABC的角平分線與∠ACB的外角∠ACD的平分線交于A₁.

（1）當(dāng)∠A為70°時(shí)，則
∵∠ACD-∠ABD=∠        ，
∴∠ACD-∠ABD=         °
∵BA₁、CA₁是∠ABC的角平分線與∠ACB的外角∠ACD的平分線
∴∠A₁CD-∠A₁BD=（∠ACD-∠ABD）
∴∠A1=          °。
（2）根據(jù)中的計(jì)算結(jié)果寫出∠A與∠A1之間等量關(guān)系                  。

如圖所示，直線a，b被直線c所截，且∠1+∠2=180°，直線a與直線b平行嗎？為什
么？

如圖所示,將△ABC沿EF折疊,使點(diǎn)C落到點(diǎn)C′處,試探求∠1,∠2與∠C的關(guān)系.

如圖所示,直角坐標(biāo)系中，△ABC的頂點(diǎn)都在網(wǎng)格點(diǎn)上，其中C點(diǎn)坐標(biāo)為（1，2）.

【小題1】寫出點(diǎn)A、B的坐標(biāo)；
【小題2】將△ABC先向左平移2個(gè)單位長度，再向上平移1個(gè)單位長度，得到△A′B′C′，分別寫出△A′B′C′的三個(gè)頂點(diǎn)坐標(biāo)；

如圖，已知AD⊥AB，DE平分∠ADC，CE平分∠BCD，且∠1+∠2＝90°，那么BC⊥AB，說明理由。

如圖所示，在平面直角坐標(biāo)系xOy中，A（-1，5），B（-1，0），C（-4，3）.

【小題1】求出△ABC的面積；
【小題2】在圖中作出△ABC關(guān)于y軸的對(duì)稱圖形△A₁B₁C₁；
【小題3】寫出點(diǎn)A₁，B₁，C₁的坐標(biāo).

下列選項(xiàng)中表示的數(shù)，哪一個(gè)是整數(shù)（　　）

A．

B．

C．

D．

若方程x²=m的解是有理數(shù)，則實(shí)數(shù)m不能取下列四個(gè)數(shù)中的（　　）

A．1

B．4

C．

D．

大課間活動(dòng)在我市各校蓬勃開展．某班大課間活動(dòng)抽查了20名學(xué)生每分鐘跳繩次
數(shù)，獲得如下數(shù)據(jù)（單位：次）：50，63，77，83，87，88，89，91，93，100，102，111，
117，121，130，133，146，158，177，188．則跳繩次數(shù)在90～110這一組的頻率是（　�。�

A．0.1

B．0.2

C．0.3

D．0.7

閱讀下面短文，根據(jù)所給語境，按要求完成下列各題。
Mozart was born on January 27, 1756 and died on December 5 , 1791. When he was three, he often had lessons with his elder sister. （1）His father took him through many different countries, where he played music for lots of people.
But some people didn’t believe a little boy could write such beautiful music. They asked him to stay in a room all by himself for a week and somebody watched the room all the time .（2） In a week , he finished a new piece of music . After that, people believed that he could write beautiful music.
Mozart died when he was still a young man. During his short life he studied music and taught music and played music and wrote music. Even by working so hard, he couldn’t make much money . Often he had to borrow money from his friends. But his music made him happy and for more than two hundred years his music has made other people happy, too.
【小題1】將（1）處翻譯成漢語。
___________________________________________________________________________
【小題2】對(duì)（2）處黑體部分提問。
___________________________________________________________________________
【小題3】根據(jù)短文內(nèi)容，完成下面的句子。（每空一詞）
Mozart was a __________ talent（天才）,but he still lived a ________ life.