国开在线答案
- 2022-09-12 [单选] —Canyougoskatingwithusthisafternoon? —Sorry,Ican’t.I________takecareofmylittlesisterathome.
- 2022-09-12 [简答] 二、阅读理解：阅读下面的短文，根据文章内容从A、B、C三个选项中选出一个最佳选项。Thehousesweliveinarevery.Theykeepusfrombeingcoldinthewinterandhotinthesummer.Inthewintertheykeepoutofthesnow.Theyalsokeepoutthewind.Evenifitisblowingoutside,weareniceandwarminside.Inthesummerhouseskeepthehotsunfromus.Whenitrains,theykeepusfromgettingwet.Housesarealsoplaceswefeelsafe.Peoplecan’tgetatusorourthings.Housesgiveusaplacetobetogetherwithourfamiliesandfriends.Mothersandfatherstheirchildrenthere.Thechildrenplaythere.Thefamilyeatandsleepunderthesameroof.Housesaredifferentinmanyways.Theyaremadeofdifferentthings.Somehousesaremadeofwood.Somearemadeofstones.Sometimesmorethanonethingisusedtomakeahouse.Housescomeindifferent.Somehouseshaveonlyoneroom.Somehouseshavemorethanoneroom.Bigbuildingsfoundincitieshaveagreatmanyrooms.Theyholdmanyfamilies.Theroomsinwhicheachfamilylivesarecalledanapartment.Housesaredifferentinthewaystheyare.Housesintropiccountriescanbelightlybuilt.Inplaceswhereitrainsmuchofthetime,housesmustkeepoutthewater.takecare(“注意”，“当心”，“留心”)
- 2022-09-12 [单选] 三阶行列式的余子式M23=（ ）．xingkao1/1121.png
- 2022-09-12 [单选] 设A为3×4矩阵，B为4×3矩阵，则下列运算可以进行的是（ ）.
- 2022-09-12 [单选] 设，则BA-1（ ）.xingkao1/1161.png
- 2022-09-12 [单选] 设A,B均为n阶可逆矩阵，则下列运算关系正确的是（ ）．
- 2022-09-12 [单选] 设A,B均为n阶方阵，满足AB=BA，则下列等式不成立的是（ ）．
- 2022-09-12 [单选] 方阵A可逆的充分必要条件是（ ）．
- 2022-09-12 [单选] 二阶矩阵（ ）．xingkao1/11141.png
- 2022-09-12 [单选] 向量组的秩是（ ）．xingkao1/11161.png