enjoy learning English , _______it takes me a lot of time.

―Tomorrow is Sunday, shall we go to the World Park―Oh, no, I don’t want to go there again. I ____________ it twice.

_______ of volunteers will be needed for 2014 International Horticulture Exposition in Qingdao.—Let’s go and _______ them.

Where did they suggest _____during the summer holidays? [ ]

Now more and more people have come to know the role that trees _____in our natural environment.[ ]