You can use a large plastic bottle, _____ cut off, as a pot to grow young plants in．
| A．the top is | B．the top of which |
| C．whose top | D．with its top |
By the time you ____ in, I ____ two letters.
| A．had come, had written | B．came, wrote |
| C．come, have written | D．came, had written |
To ____ your dream of becoming a scientist, you must work hard from now on.
| A．turn | B．recognize | C．live | D．change |
.I suggest ______10% of the bill for the waiter or waitress if a tip isn’t included.
| A．to leave | B．leave | C．being leaved | D．leaving |
There are _____advertisements which encourage ______to participate in improving their neighbourhood.
| A．the public,the public | B．the public,public | C．public,public | D．public ,the public |
Some advertisements_______pictures or words of experts to show people how good the products are.
| A．are consisted of | B．are made of | C．consist of | D．are made up |