Danny's class 1have a party. Danny wants to make a special cake2 the party. He wakes up early in the morning. He won't be 3. Danny begins 4the cake. He puts some flour(面粉), oil(油), milk and a little salt(盐) 5 the bowl(碗). He makes a picture6 it. It 7 like the flag of Canada. But he forgets 8 the sugar. There is 9 in the cake, too. Every piece of the cake 10 a cent in it.

下列有关植物组织培养的叙述，正确的是 （    ）