获知一种粒子的阈温，除了需要知道粒子的质量之外，最关键的常数是玻尔兹曼常数和光速。
参考答案：对
Change the sentences.
1. It took the Clarks two hours to clean their kitchen last Saturday.
The Clarks __________ two hours __________ their house last Saturday.
2. When I read love stories, I feel moved.
Reading love stories often __________ me __________.
3. When does the train leave? I want to know. (Put the two sentences together.)
I want to know __________ the train __________.
关于下图的有关叙述不正确的是（）
A.过程①获得的DNA称为cDNA
B.过程③需事先对大肠杆菌用CaCI2处理，使其处于感受态
C.过程④动物细胞培养需加血清
D.过程⑤导入的受体细胞是乳腺细胞
