题目

计算 (1) (2) (3) (4) 答案:解: (−3.14)+(+4.96)+(+2.14)+(−7.96) =(−3.14+2.14)+(−7.96+4.96) =−1−3 =−4 ; 解: −999899×9 =(−100+199)×9 =−100×9+199×9 =−900+111 =−8991011 ; 解: [2−5×(−12)2]÷(−14) =(2−5×14)×(−4) =2×(−4)−5×14×(−4) =−8+5 =−3 ; 解: −0.252÷(−12)4×(−1)7+(118−113−334)×24 =−(14)2÷(116)×(−1)+(98−43−154)×24 =116×16×1如图为鸡卵的结构图,请据图回答以下问题:(1)填写图中各结构的名称.②________    ⑦________(2)在鸡的受精卵中,能发育成胚胎的是[⑤]________.(3)鸡胚胎发育所需的养料由[④]________和[⑥]________供给.
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